Different types of drawings is used in construction such as architectural drawings, structural, electrical, plumbing and finishing drawings. These drawings provides layout plans and details for construction of each and every part of the building.
Drawings plays an important role in the construction field to convey the ideologies and perspective of the designer to the layman at site. The drawings may be used to indicate the overall appearance, inside or outside the structure, or they may be used to indicate precise measurements and other details for construction.
Types of Construction Drawings
1. Architectural Drawing
1.1 Site Plan
This is primary drawing used for marking out the plan on the ground. It represents the location, orientation and information about the site’s topography, landscaping utilities ,and site work.
1.2 Working Plan
1.3 Section Drawings
1.4 Elevation Drawing
2. Structural Drawing
2.1 General Note
This is more of a codes and by laws of the buildings. No drawing is found in this, but the details of all the structural drawings are mention in this such as concrete mix, lapping length, curing time, abbreviation, codes and other work procedures.
2.2 Excavation Drawing
This drawing represents the footing excavation dimension, column position, footing plan and grid lines of column.
2.3 Column Layout
This drawing represents the position and orientation of columns and column reinforcement details.
2.4 Plinth Beam Layout
This drawing represents the dimensions, position and section of plinth beam and the details of reinforcement in plinth beam.
2.4 Lintel Beam Layout
This drawing represents the dimensions, position and section of lintel beam and the details of reinforcement in lintel beam.
2.5 Roof Beam and Shuttering Layout
This drawing represents the details of reinforcement of roof beam, its section and shuttering details.
2.6 Roof Slab Layout
This drawing represents the details of reinforcement of roof slab, its section and openings in the roof for various purpose such as stairs or skylight.
3. Electrical Drawing
Electrical drawing represent the details of electrical fixtures, location of switches, fan, light and others. It also represents the load calculation, tapping for electricity, wiring path and other interventions such as AC and UPS and its components.
4. Plumbing Drawing
Plumbing drawings give the location of sanitary, piping for water supply system, fixture, and the process to connect every fixture.
5. Finishing Drawings
Finishing drawings represents the finish type of every component of the building such as flooring pattern, painting color, false ceiling shape, plastering texture and elevation design. These details are sometime given in elevation drawings also.
There is no standard rule of drawings required for a project. Depending upon the type of building and requirement, types of drawings are made and issued .
Methods of Estimation for Building Works?
The estimation of building quantities like earth work, foundation concrete, brickwork in plinth and superstructure etc. can be worked out long wall short wall method and centerline method.
Following are the three different methods used for estimating building works:
- Long wall – short wall method
- Centreline method.
- Partly centre line and short wall method.
Long Wall – Short Wall Method
In this method, the wall along the length of room is considered to be long wall while the wall perpendicular to long wall is said to be short wall.
To get the length of longwall or shortwall, calculate first the centre line lengths of individual walls. Then the length of long wall, (out to out) may be calculated after adding half breadth at each end to its centre line length.
Thus the length of short wall measured into in and may be found by deducting half breadth from its centre line length at each end.
The length of long wall usually decreases from earth work to brick work in super structure while the short wall increases. These lengths are multiplied by breadth and depth to get quantities.
Centre Line Method
This method is suitable for walls of similar cross sections. Here the total centre line length is multiplied by breadth and depth of respective item to get the total quantity at a time.
When cross walls or partitions or verandah walls join with main wall, the centre line length gets reduced by half of breadth for each junction.
Such junction or joints are studied carefully while calculating total centre line length. The estimates prepared by this method are most accurate and quick.
Partly Centre Line and Partly Cross Wall Method
This method is adopted when external (i.e., around the building) wall is of one thickness and the internal walls having different thicknesses. In such cases, centre line method is applied to external walls and long wall-short wall method is used to internal walls.
This method suits for different thicknesses walls and different level of foundations. Because of this reason, all Engineering departments are practicing this method.
Why Concrete Cracks?
Cracks in concrete are extremely common but often misunderstood. When an owner sees a crack in his slab or wall, especially if the concrete is relatively new, he automatically assumes there’s something wrong. This is not always the case. Some types of cracks are inevitable. The best that a contractor can do is to try to control the cracking. This is done by properly preparing the subbase, assuring that the concrete is not too wet, utilizing reinforcement where needed, and by properly placing and spacing crack control joints and expansion joints. However, sometimes cracks happen in spite of any precautions taken.
The American Concrete Institute addresses this issue in ACI 302.1-04. “Even with the best floor designs and proper construction, it is unrealistic to expect crack-free and curl-free floors. Consequently, every owner should be advised by both the designer and contractor that it is normal to expect some amount of cracking and curling on every project, and that such occurrence does not necessarily reflect adversely on either the adequacy of the floor’s design or the quality of its construction (Ytterberg1987; Campbell et al. 1976)”.
Diagnosing 6 Types of Concrete Cracks
Plastic Shrinkage Cracks
Probably the single most common reason for early cracks in concrete is plastic shrinkage. When the concrete is still in its plastic state (before hardening), it is full of water. This water takes up space and makes the slab a certain size. As the slab loses moisture while curing it gets a bit smaller. Because concrete is a very rigid material, this shrinking creates stress on the concrete slab. As the concrete shrinks, it drags across its granular subbase. This impediment to its free movement creates stress that can literally pull the slab apart. When the stress becomes too great for the now hardened concrete, the slab will crack in order to relieve tension. Especially in hot weather, shrinkage cracks can occur as early as a few hours after the slab has been poured and finished.
Often, plastic shrinkage cracks are only a hairline in width and are barely visible. However, even though a crack is hairline, it extends through the entire thickness of the slab. It’s not just on the surface as one might think.
One factor that contributes significantly to shrinkage is mixing the concrete too wet. If excessive water is introduced into the mix, the slab will shrink more than if the correct amount of mix water were used. This is because the additional water takes up more space, pushing the solid ingredients in the mix further apart from each other. It’s similar to over-diluting a pitcher of Mi-Wadi. By doing so, a weaker solution is created. When the excess water leaves the slab, the solid particles have larger voids between them. These empty spaces make the concrete weaker and more prone to cracking. Unfortunately, wetter concrete is easier to place and finish, especially in hot weather. This is one reason that many concrete finishers add water to concrete mixer trucks: it makes their work easier. A few litres per cubic metre will not significantly affect the mix. However, if an excessive amount of water is added, one can unwittingly reduce the concrete’s strength.
Plastic shrinkage cracks can happen anywhere in a slab or wall, but one place where they almost always happen is at re-entrant corners. Re-entrant corners are corners that point into a slab. For example, if one were to pour concrete around a square column, you would create four re-entrant corners. Because the concrete cannot shrink around a corner, the stress will cause the concrete to crack from the point of that corner (See Figure 1).
Figure 1: Shrinkage cracks originating at re-entrant corners
A rounded object in the middle of a slab creates the same problem as a re-entrant corner. This is commonly evidenced around slab penetrations such as pipes, plumbing fixtures, drains, and manhole castings. The concrete cannot shrink smaller than the object it is poured around, and this causes enough stress to crack the concrete (See Figure 2).
Figure 2: Shrinkage crack at slab penetration
To combat random shrinkage cracks, control joints (often mistakenly referred to as expansion joints) are incorporated into the slab. Control joints are actually contraction joints because they open up as the concrete contracts or gets smaller. They are simply grooves that are tooled into fresh concrete, or sawed into the slab soon after the concrete reaches its initial set. Control joints create a weak place in the slab so that when the concrete shrinks, it will crack in the joint instead of randomly across the slab (See Figure 3).
Figure 3: A successful crack control joint
For a crack control joint to be effective, it should be ¼ as deep as the slab is thick. That is, on a typical 100mm thick slab, the joints should be no less than 25mm deep; a 150mm thick slab would require 38mm deep joints, etc. To minimize the chances of early random cracking, these joints should be placed as soon as possible after the concrete is poured. If the control joint is not deep enough, the concrete can crack near it instead of in it (See Figure 4).
Figure 4: A crack next to a too-shallow joint
Crack control joints should be placed at all re-entrant corners and slab penetrations, and evenly spaced throughout the rest of the slab. A good rule of thumb for 100mm thick residential concrete is to place joints so that they separate the slab into roughly equal square sections, with no joint being further than about 3 metres from the nearest parallel joint. Following these guidelines, a 1.2 metre wide footpath would be cross- jointed at 1.2m intervals. A 4.8 m x 19.2m driveway would have one joint running up the centre length ways, and joints cut across it every 2.4 metres . This pattern would create sixteen 2.4m x 2.4m sections. If a driveway is metre wide or less, the centre joint up its length can usually be safely omitted, and the cross joints spaced the same distance as the driveway is wide (for example, an 3 metre wide driveway would have no centre joint and cross joints every 3 metres). If joints are not placed where they need to be, the concrete will create its own joints by cracking. It’s interesting to note that it often cracks in the same pattern as it should have been jointed (See Figure 5).
Figure 5: Driveway cracks where joints should have been placed
Another reason that concrete cracks is expansion. In very hot weather a concrete slab, like anything else, will expand as it gets hotter. This can cause great stress on a slab. As the concrete expands, it pushes against any object in its path, such as a brick wall or an adjacent slab of concrete. If neither has the ability to flex, the resulting force will cause something to crack.
An expansion joint is a point of separation, or isolation joint, between two static surfaces. Its entire depth is filled with some type of compressible material such as tar-impregnated cellulose fibre, closed-cell poly foam, or even timber (See Figure 6). Whatever the compressible material, it acts as a shock absorbed which can “give” as it is compressed. This relieves stress on the concrete and can prevent cracking.
Figure 6: Foam expansion joint separating driveway and curb.
Expansion joint material can also prevent the slab from grinding against the abutting rigid object during periods of vertical movement. During these times of heaving or settling, expansion joint material prevents the top surface of the slab from binding up against the adjacent surface and flaking off (See Figure 7).
Figure 7: Expansion joint between these slabs would have prevented chipping
Cracks Caused by Heaving
Another factor which contributes to cracking is ground movement brought on by freeze/thaw cycles. During such cycles, the frozen ground can lift as much as several inches, and then settle again when the ground thaws. If the slab is not free to move with the soil, the slab will crack. The presence of large tree roots can also cause concrete to heave. If a tree is located too close to a concrete slab, the growing roots can lift and crack the concrete (See Figure 8).
Figure 8: Tree roots lifted and cracked this sidewalk
Cracks Caused by Settling
Conversely, if a large tree is removed from near a concrete slab the buried roots will decompose. The resulting void can cause the ground to settle and the concrete to crack. Settling is also called subsidence.
Subsidence is very common over trenches where utility lines and plumbing pipes are buried. Often times, the utility trench is not compacted when it is refilled. If concrete is placed atop a poorly compacted trench, the void created by subsidence can cause a crack across the unsupported concrete slab (See Figure 9).
Figure 9: Crack across the unsupported concrete slab.
Another place where concrete commonly subsides is near a house. Whether the home is built on a basement or crawlspace, the over-dig is subsequently back filled. Unless the back fill material is compacted in lifts as the over-dig is filled, it will settle over time. This settling will cause any concrete poured atop it to settle along with it. Many times this settling will cause the concrete to crack and tilt back toward the house, creating negative slope (See Figure 10).
Cracks Caused by Overloading the Slab
Another factor which contributes to cracking is placing excessive weight on top of the slab. Although it is a very strong material, concrete still has load limits. When you hear someone speak of 4,000 psi concrete, they are referring to the fact that it would take 4,000 pounds per square inch of pressure to crush it. Residential concrete, however, is rarely overloaded as far as compressive strength is concerned. That is to say, the weight doesn’t usually pulverise or crush the concrete. What is more common is that the excessive weight is too much for the ground underneath the concrete. This is especially true after periods of heavy rain or snow melt when the ground is saturated and soft.
When groundwater migrates under the concrete it causes the underlying soil to become soft or spongy. Excessive weight on the slab at this point can press the concrete down. Since the flexural strength of concrete is less than its compressive strength, the concrete bends to its breaking point. Homeowners who place large recreational vehicles or dumpsters on their driveways are more likely to see this type of cracking. Driving heavy vehicles off the edge of a slab creates a similar type of crack.
Figure 12: A heavy truck drove over this sidewalk, cracking the edge
Cracks Caused by Premature Drying
Crazing cracks are very fine surface cracks that resemble spider webs or shattered glass. They can happen on any concrete slab when the top loses moisture too quickly. Crazing cracks can be unsightly, but are not a structural problem. They are so fine that there is no way to repair them (See Figure 13).
Crusting cracks often happen during the concrete stamping process. They usually occur on sunny or windy days when the top of the slab dries out sooner than the bottom. The top becomes crusty so when the stamp is embedded, it pulls the surface apart near the stamped joints causing small cracks around the outside edges of the “stones”. Although they are cosmetically unappealing, crusting cracks present no structural problem but may be patched if desired
Figure 14: Crusting cracks caused by premature surface drying
The Importance of Reinforcement
The use of synthetic fibers, reinforcing wire mesh, or rebar can add some extra support to concrete, but none of them will prevent cracking. In fact, too much steel can actually cause a slab to crack by restraining normal concrete shrinkage. However, if cracks happen, reinforcement can hold the different sections together.
The presence of reinforcement can be the difference between a crack remaining hairline in nature or separating and becoming wider and unsightly. Steel reinforcement can also keep the concrete on both sides of a crack on the same horizontal plane. This means that one side doesn’t heave or settle more than the other, which could cause a tripping hazard. It is sometimes impossible to determine exactly what caused a particular crack. However, proper site preparation and good concrete finishing practices can go a long way towards minimizing the appearance of cracks and producing a more aesthetically pleasing project.
Source : Ardex Building Products
50 Project Management Terms You Should Know
By Neeru Jain – February 14, 2018 PROJECT MANAGEMENT
Project management is a set of important skills for most of the careers. It is the application of processes, knowledge, skills, and experience to reach the project goal. Main components of project management are:
- Outlining the basis why a project is essential.
- Determining the project requirements, the standard of deliverables, resource allocation, timescales etc.
- Controlling risks, issues, changes in project and managing project budget as planned
- Providing communication with project team and stakeholders
- The closing of the project in a controlled manner at the proper time.
50 Project Management Terms You Should Know
Every course has its own glossary, and hence project management is not an exemption. Project Management glossary contains a number of project management terms that will help the project team to standardize the project’s startup process. These project management terms are the popular project management buzz words. Here we have given top 50 project management terms that you should know-
1. WBS (Work Breakdown Structure)
Work Breakdown Structure is one of the important project management terms. A work breakdown structure (WBS) is hierarchical that breaks down the work into manageable clods so that each level of WBS could be easily understood by the project team. Project team creates WBS by analyzing major deliverables and then dividing them into sub-deliverables. This dividing process is continued until it is assigned to a single person.
Do you know about communication methods in project management? If no, read the article – Communication methods and its importance in project management.
A milestone is a scheduling process that describes the set of related deliverables. These are the significant points in time or an event that mark important moments during the project. This is a best practice for project managers to use a milestone in the project to celebrate something expressive being created. Milestone is one of the components of Gantt chart and you will be able to see them on the project schedules presented as a diamond. These are mainly used for
- Starting phase
- Ending phase
- Fixed dates on plan
Stakeholders are very important in project management, thus stakeholder is one of the project management terms you should know. Stakeholders are the people engaged in and influenced by the project. Some of the stakeholders cover every section of the organization whether some have limited scope. Some of them are outsiders as government bodies. They must be informed about the necessary information. To deliver a product on the basis of customer’s demand is not enough for the success of a project. Projects must meet all the expectation of stakeholder.
4. Work Plan
One of the key terms of project management is its work plan. A work plan is an outline of a group of goals with the help of which project team can reach those goals. The aim of the project work plan is to promote efficiently, systematized and completion of the project according to budget, schedule, and requirements. It presents all the tasks involved in a project, who is responsible for each task and when these tasks will be completed. It includes the job scope, work product definition, task sequencing, budget, schedule etc.
The baseline is one of the most popular project management terms among project managers. A baseline is used to measure the performance of the project. There are three baselines in project management. These are –
- Schedule baseline
- Cost baseline
- Scope baseline
The combination of these three is considered as complete performance measurement baseline.
6. Triple Constraint
All the projects are brought about under some constraints. Triple constraint is a four components group (time, scope, cost and quality of the product) represented by a triangle with time, scope and cost at corner side and quality at the central theme. There must a balance among all these components as the change in any one will impact the other components.
- Project Management Terms
- Components of Triple Constraint
7. Project Life Cycle
The project life cycle is among some important project management terms you should know. It includes project planning, analysis, design, implementation, and budget. A project life cycle can have many models but each model represents a single phase to build the deliverables of the project. A project life cycle consists of initiating the project, it’s planning, monitoring and controlling, executing, and closing.
project management phases
8. Gantt Chart
Gantt chart is a bar chart that displays the scheduled information graphically. These are very useful in the planning and scheduling of the projects. It is also helpful in managing the relationship between tasks. This chart can be used to keep the project team and sponsors informed about the project progress. Using the Gantt chart, one will be able to see what is achieved by a certain date and, if the project is behind the schedule then an action can be taken to bring it on track.
9. Change Management
Change management is one of the project management buzz words. It is a project management plan that has authority to approve or reject the changes on the project. Purpose of this management is to manage the change that occurs during project according to the previous planned requirements and statements. If change management approves the new change in the project, only then the project manager will be able to modify the budget and deadline to reflect the additional work.
10. Risk Mitigation
At the beginning of the project, it is important to know the risk that surrounds the project because you can change your plan or can choose some other option to avoid the risk occurrence. And, risk mitigation is that project management term which identifies the risk. It is a risk reaction devising technique associated with menace to the project. If risks are not identified then it can cause a failed project by taking so much time as you are not prepared for that. So, this risk mitigation, risk identifying term is of much use as this idea reduces the possibility of occurring risk and also reduces the imprint of risk on the project.
During the course of a project, Work or Work Package consists of an Activity. Sometimes it is defined as the smallest part of a project. It identifies the timeline development, accurate estimating and many other aspects by turning into small tasks. Activity has a unique function i.e. sequencing. Along with Work Breakdown Structure (WBS), it states two main processes: Identification and Documentation.
While dealing with statement of work (SoW) and working on a project, Assumptions are listed as factors. It ensures the validation and result of projects. Assumption Analysis is a practice in which one can identify or calculate the accuracy part.
Agile is an approach particularly used for product and project management. Sprints are used in terms of short bursts of work typically in an iterative way to deliver software projects. Agile was initially developed for Engineering and Information Technology projects. But with the continuous innovation, marketing industry is also currently using it successfully. Agile’s approach is making its mark rapidly because it gives a flexible working style. It comes under the most popular project management terms.
Before executing or designing a project, a complete SWOT analysis should have to be performed by teams involving in the same project. The technique used to calculate solutions, risks etc. by professionals is known as Brainstorming. It is basically an analysis method.
15. Business Case and Use Cases
Business Case is referred to a doc file which is used to store data like costs, calculations, benefits etc. Moreover Use Cases also help users by providing the requirement of software tests. These requirements are directed from end consumer directly. Use cases also concentrates on daily actions.
16. Business Plan
Business Plan is termed as a doc file which evidently describes about the project goals. It includes the business goals and their strategies to achieve them. Business Plan also concludes contextual info.
17. Certified Associate in Project Management (CAPM)
CAPM is generally found among the project management buzz words. Certified Associate in Project Management is an entry-level project management certification offered by Project Management Institute (PMI). This is a knowledge guide by the Project Management Institute to provide an associate level certification.
18. Contingency Plan
Contingency plan refers to the second plan if your plan A doesn’t work. It includes the situations which may or may not occur in future. Contingency plan provides solutions to exceptional risks. These risks have disastrous concerns. Thus it also includes the risks management. Contingency Plans are often designed by officials who are in businesses or Governments. It is sometimes referred to an alternative action.
19. Cost Estimation
Cost estimation is one of the most popular project management terms among project managers. Cost is the factor which is the most important for any business. It can impact profit and time duration of the project. So, cost estimating is the key method which is used to calculate entire project cost.
20. Critical Path Method (CPM)
Critical Path Method (CPM) provides functions to write an algorithm for project activities. It is particularly used for scheduling and termed as the “critical or shortest path”. Critical Path Method (CPM) is a step by step approach in which one can analyze critical and non-critical tasks.
21. Case Study
Case study comes among the important project management terms. Case Study is a process in which an individual or a team conducts a research on particular project to analyze its crucial aspects. It basically consists of document files consisting of approaches, practices, and product specifications.
22. Closing Processes
Closing Process is described as the termination of a project along with all the phases and processes. It is the end of the project that denotes the successful completion of the project. In the five steps of project management life cycle, closing process is the last step.
Also Read: 10 Steps at the Time of Project Closure
23. Dummy Activity
Before going through final activities, every project manager suggests dummy activities. Dummy Activities are shown with dashed lines. Dummy Activities are used after a failure, to describe that.
Dashboard is basically a platform which helps to check all the useful information about the project. Through dashboards, anyone can view data from their location. It is used to check KPIs where KPIs stands for Key Performance Indicators. Dashboard monitors all the reports and allows users to regularly update. Dashboards are categorized as Informational, Planned, Logical or Operational.
For every tasks or projects, there is a commitment of required result/output which is to be delivered to the users. That required output is known as deliverables. Deliverable is referred to perceptible or imperceptible objective which is the most important for a successful project. A document, A Report, End Product or Project Block are the best examples of Deliverables. It can be categorized in terms of Software, Hardware and design documents.
26. Earned Value & Earned Value Management (EVM)
Earned Value is termed as the methodology in which three main aspects of projects i.e. the actual work, project plan & value at which work is completed, are observed. It also demonstrates the timeline and total costs that have been spent on the projects. Moreover, Earned Value Management (EVM) is a process where one can schedule, measure, and check scope of performances.
27. Feasibility Study
Feasibility Study is among the most popular project management terms. It is defined as the process of assessment of a designed plan. It is a methodology in which you can see everything practicality. It consists of the activities like market research, polls, detailed project study etc.
28. Human Resource Planning
Human resource is responsible for the manpower and their deployment. In human resource planning, you can identify the individual roles. Also, you can observe the relationships between individuals who are related to the project.
29. Network Diagram
Network Diagram is a graph or chart which clearly indicates the flow of elements in the project. It also consists of the elements that are shown from left to right with their dependencies.
30. Organizational Breakdown Structure (OBS)
Organizational Breakdown Structure (OBS) is defined as the organization of a project in hierarchical depiction. It can rely on work packages to perform all the organizational activities.
31. PERT Chart
PERT Chart is used to evaluate the reviews. It is also known as Program Evaluation Review Technique. PERT Chart is used to create, establish, and organize tasks. A precedence diagram, a network chart, and logic diagram can be created in the PERT Chart.
32. PERT Estimate
PERT estimate is used to calculate time and costs. It is actually an accurate estimating technique. “Pessimistic plus the optimistic, plus four times the most likely, divided by six.” is the main formula used in PERT. PERT Estimate uses a prejudiced middling to expect the longevity of a task.
PRINCE2 refers to Projects In Controlled Environments – version 2. It is a formal project approach which provides functions like Planning, Monitoring, and Controlling. It encourages individuals or teams to attain their goals timely. It also takes care of budget. It is also termed as a certification which is essential for UK and Europe project managers.
34. Project Management Body of Knowledge (PMBOK)
PMBOK is one of the most popular project management terms among the project managers. Project Management Body of Knowledge (PMBOK) is a guide which concludes terms, best practices, strategies and procedures. This guide is a standard guide provided by The International Organization for Standardization and followed by the industry.
35. Project Management Professional
Project Management Professional indicates to an individual who is an expert professional. He/She is a certified project manager who is responsible for all the activities, elements, strategies etc. The category of certified project manager includes all the associate and professional level candidates.
What is the best strategy to prepare for PMP? Read here.
36. Project Change Request Form
Formalizes requests from anyone to the project manager. It requires the requestor not only to describe the change, but also to supply a reason why this change is appropriate and needed. Once the requestor has completed the form, the project manager can determine whether the change is indeed necessary, should be rejected, or should be delayed until the completion of the current project.
37. Project Management and Knowledge Area
An application consists of few key points: information, services, tools, and methods. These applications are defined by the Project Management Institute (PMI). Project Management also achieves the expectations of stakeholders. There is an area defined for project management for the knowledge requirements.
38. Project Manager
Project Manager is an individual who is responsible for a project . He/She is responsible for aspects like execution, planning, and closure of a project. There are various occupations like healthcare, information technology, architecture and others that requires Project Managers. No doubt, project manager is worth to be included in the list of top project management terms.
Scrum is an important approach in Agile. It is used for delivering software products with iterative incremental process. Scrum basically follows Rugby stint in which teams use short sprints. Short Sprints are useful for delivering a steady progress in a strong leadership. The leader in Short sprints is referred as Scrum Master.
40. Quality, Quality Assurance, and Quality Control
Quality is an interpretation which defines superiority and inferiority of things. Quality gives products’ sustainability, maintainability, and reliability. It also pre-decides the requirements which inherits characteristics. Quality Assurance refers to the approach which includes prevention of errors. It maintains the preferred level of the quality. Quality Control refers to the procedures which certifies that product defines the necessary goals.
41. Risk Management
In every project, you can have some risks. To reduce risks, there are few methods where you can manage risks. Also you can write down the potential risks occurred in the project and through the management tools, you can reduce them easily. Risk management is worth to be included in the list of top project management terms.
Reporting is an essential part in any project. Reporting is basically a document file in which every information about the project is stored with the development records. At every phase, one should report to the project manager so that every team which involves in the same project can gather.
43. RACI Chart
An RACI chart is defined as a matrix in which you can get all the significant actions happening in a project. It is bifurcated according to the roles or people. Also in matrix and at each intersection, you can allocate responsibility to anyone.
44. Resource Calendar
Resource calendar is termed as the list of working days along with non-working days which specifies the activity of resources. It is particularly used to calculate the holidays.
45. Statement of Work (SoW)
SoW stands for the Statement of Work. It describes the method and production of the project. It is basically a tool by which you can directly work with anyone. You just need to enter the description of tasks which is to be done.
46. Status Reports
Status reports deliver existing info on the project charge, financial plan, possibility, and other pertinent info. It also includes the completed tasks and tasks in future. It also includes a risk list and project duration.
47. SWOT Analysis
if you are in project management, SWOT analysis is among the project management terms you should know. SWOT stands for Strengths, Weaknesses, Opportunities and Threats. Before starting a project, there should be a SWOT analysis so that you can have all the required terms of the project and you can calculate the key terms. The SWOT analysis refers to the planning by which you calculate these terms.
48. Time Management
When a project is designed and delivered to the team for reference, then it consists of the time duration which every team should follow. It also indicates the method of scheduling and management of time of the project. It also involves the project manager, management and all the key personnels who are responsible for the project. It helps to calculate the team efficiency.
49. Three-Point Estimation
Three point estimation is a method or process by which you can take reviews or cases. Mainly known Three Point Estimations are best-case, worst-case, and most likely case. It helps enterprises to generate accuracy, calculate estimation, and average.
50. Waterfall Model
In Waterfall Model, There are various phases which need to be followed from sequentially one phase to the next. Waterfall Model is a traditional project management procedure in which sequential development process is followed. Also in this model, development actually moves in downward direction. It also consists of few phases like initiation, analysis, design, build, test, and maintenance. Besides, agile model is preferred over waterfall model now-a-days, waterfall model is always there in project management terms cheat sheet.
To deliver a project successfully, it is important to start the project with proper identification and pre-defined goal. For this, it is required to know and understand the project management terms. This article is the project management terms cheat sheet for those who are not familiar with the project management. Here, we have covered all the project management terms that you should know. So, give a good start to your project management career by reading these important project management terms.
Is Water Good or Bad in Concrete?
Trick question! The answer is both. Water is needed, but after the need is met, it begins to hurt the concrete.
There are two types of water in concrete: water of necessity (also known as water of hydration) and water of convenience.
Water of Necessity
The main ingredients of concrete are fine aggregate (sand), coarse aggregate (gravel or stone), cement and water. When water comes in contact with cement, it begins a chemical process called hydration. This process forms crystals that bind the coarse aggregates together. Hydration is how concrete gains its strength. A certain amount of water is required to full hydrate the cement so that all the cement is used to bond the concrete mix together. This is commonly referred to as a water to cement ratio. The ratio is calculated by taking the weight of the water and dividing it by the weight of the cement. The minimum water to cement ratio required for hydration is a 0.28. Any additional water is water of convenience.
Water of Convenience
While a low water to cement ratio is optimized for performance, the mix is very stiff and difficult to work with. It has what we call a low slump. That is a measure of how far a cone of wet (or plastic) concrete will fall when the cone is removed. A low slump of an inch is very stiff, whereas a high slump of 6 inches would flow quite easily. Think of it like a pancake batter. If the pancakes are too stiff, adding more milk to make it flow more so it is more workable. Unfortunately, that has a significant down side.
How Does Water Hurt Concrete?
So now we know why we need water for hydration, what is the down side to adding as much water of convenience as we can? All of the excess water that is in the mix will need to leave the concrete in the form of what is called bleed water. This has negative effects. Adding just one gallon of water to a cubic yard of concrete will:
- Increase the slump about 1 inch
- Decrease compressive strength about 200 to 300 psi
- Increase shrinkage potential by as much as 10% (increased cracking) – Think about how the concrete is changing size while all that water bleeding out at the same time it is trying to get hard.
- Decrease resistance to de-icing salts
- Decrease wear resistance to traffic
- Increase dusting and other surface defects
- Increase time needed to cure the concrete
How Can I get the Good Parts of Water without the Bad?
The good news is that you can have your cake and eat it too! There are chemical admixtures called normal water reducers and high range water reducers that we can put in the concrete. Concrete designed for slumps greater than 5 inches typically will require the use of a high range to avoid having a high water cement ratio. Depending on the required slump, these water reducers will increase the slump and fluidity of the concrete without extra water and all its negative effects.
It’s important to know how much slump you want with your concrete when you order it, so we can help you pick a mix optimized for your needs so you don’t feel that you have to add water at the job site and decrease the quality of your concrete.
Source : Chaney Enterprises
Inspection of concreting works is an important step to achieve greater strength and durability of the structure. Although it is easy to remember number of checks during inspection of concrete member, a checklist is always required for record of the placement of concrete and quality control measures taken at site.
Stages of Inspection of Concrete Works
Inspection of concrete is done in 3 stages,
- During placement
Type of inspection of concrete depends on type of concrete, i.e. PCC or RCC, type of elements to be casted, such as RCC slab, columns, footing, beams, walls etc. It is both beneficial to contractor as well as engineer to maintain the record of checks, so that they can produce it in case of any discrepancy.
It also allows becomes a proof of quantity of concrete work done by the contractor, so that no discrepancy arises during billing.
The checklist also notes the number of cubes taken for the given work and its id is noted in the checklist, so that when cube test results arrive, it becomes easy to identify the structural elements for the given cube test results.
1. Concrete Pre-Placement Checklist
Table 1: Standard Inspection Checklist for pre-placement of concrete.
|1||Centre line||As per drawing|
|2||Formwork & Staging||As per drawing & in exact plum|
|3||Construction joint location*||As per drawing|
|4||Steel reinforcement diameter / spacing & coating*||As per drawing|
|5||Cover to the reinforcement and overlap*||As per drawing|
|6||Shuttering||Aligned as per drawing and in plumb|
|7||RLs and reference levels||As per drawing|
|8||Embedment part check, i.e. insert plates, nipple etc||As per drawing|
|9||Placement of water stoppers, if any*|
|10||Location of construction joint|
|11||Water tightness of shuttering, if required||No water seepage allowed|
|12||Quality of water||Potable and clean|
|13||Measuring jar for water pouring||As per water content requirement|
|14||Quality of materials||As per specification|
2. Inspection during Placement of Concrete
Table 2: Standard Inspection Checklist during placement of concrete
|1||Water cement ratio||As per specification|
|2||Surface preparation by mortar bedding||Fresh mortar|
|3||Slump testing*||As per requirement|
|4||Adequacy of vibration||40mm and 60mm needle required|
|5||Segregation of aggregates||Not allowed|
|6||Removal of temporary spacers and ties*||To be removed|
|7||Check for shuttering prop displacement / settlement||Not Allowed|
|8||Number of cubes taken for testing with identification No.: ________ Id: __________||3 No’s for RCC > 6m33 No’s for every 5m3|
|9||Continuity of operations||No break in between concreting|
3. Post placement Concrete Inspection Checklist
Table 3: Standard Inspection Checklist for Post placement of concrete.
|1||Observation for honeycombing||Not Allowed|
|2||Line and Level||As per drawing|
|3||Surface finish||As per drawing|
|4||Cracks and air bubbles||Not Allowed|
|5||Method of curing||As specified|
|6||Checked for stripping/Removing of formwork support etc. after specified duration of stripping time.||Yes||No||NA|
|7||Checked for position of embedment||Yes||No||NA|
|8||Repair and finish all surface defects by specification / approved method||Yes||No||NA|
|9||Surface of part of structure is alright and allowed for subsequent activity / backfilling||Yes||No||NA|
|10||Others, if any|
* The above checklist are valid for Reinforced Concrete works only.
- All the empty space has to be filled and remarks if any shall be written in remarks column.
- Date of inspection of pre-concrete, during placement and post-concrete placement shall be noted as these steps may not be performed on the same day.
- Signature by contractor supervisor and engineer is done after each inspection.
Source : The Constructor
There are various types of cement used in concrete construction. Each type of cement has its own properties, uses and advantages based on composition materials used during its manufacture.
13 Types of Cement and their Uses
- Ordinary Portland Cement (OPC)
- Portland Pozzolana Cement (PPC)
- Rapid Hardening Cement
- Quick setting cement
- Low Heat Cement
- Sulphates resisting cement
- Blast Furnace Slag Cement
- High Alumina Cement
- White Cement
- Coloured cement
- Air Entraining Cement
- Expansive cement
- Hydrographic cement1. Ordinary Portland Cement (OPC)
Ordinary Portland cement is the most widely used type of cement which is suitable for all general concrete construction. It is most widely produced and used type of cement around the world with annual global production of around 3.8 million cubic meters per year. This cement is suitable for all type of concrete construction.
2. Portland Pozzolana Cement (PPC)
Portland pozzolana cement is prepared by grinding pozzolanic clinker with Portland cement. It is also produced by adding pozzolana with the addition of gypsum or calcium sulfate or by intimately and uniformly blending portland cement and fine pozzolana.
This cement has high resistance to various chemical attacks on concrete compared with ordinary portland cement and thus it is widely used. It is used in marine structures, sewage works, sewage works and for laying concrete under water such as bridges, piers, dams and mass concrete works etc.
3. Rapid Hardening Cement
Rapid hardening cement attains high strength in early days it is used in concrete where formworks are removed at an early stage and is similar to ordinary portland cement (OPC). This cement has increased lime content and contains higher c3s content and finer grinding which gives greater strength development than OPC at an early stage.
The strength of rapid hardening cement at the 3 days is similar to 7 days strength of OPC with the same water-cement ratio. Thus, advantage of this cement is that formwork can be removed earlier which increases the rate of construction and decreases cost of construction by saving formwork cost.
Rapid hardening cement is used in prefabricated concrete construction, road works, etc.
4. Quick setting cement
The difference between the quick setting cement and rapid hardening cement is that quick setting cement sets earlier while rate of gain of strength is similar to Ordinary Portland Cement, while rapid hardening cement gains strength quickly. Formworks in both cases can be removed earlier.
Quick setting cement is used where works is to be completed in very short period and for concreting in static or running water.
5. Low Heat Cement
Low heat cement is prepared by maintaining the percentage of tricalcium aluminate below 6% by increasing the proportion of C2S. This makes the concrete to produce low heat of hydration and thus is used in mass concrete construction like gravity dams, as the low heat of hydration prevents the cracking of concrete due to heat.
This cement has increased power against sulphates and is less reactive and initial setting time is greater than OPC.
6. Sulphates Resisting Cement
Sulfate resisting cement is used to reduce the risk of sulphate attack on concrete and thus is used in construction of foundations where soil has high sulphate content. This cement has reduced contents of C3A and C4AF.
Sulfate resisting cement is used in construction exposed to severe sulphate action by water and soil in places like canals linings, culverts, retaining walls, siphons etc.
7. Blast Furnace Slag Cement
Blast furnace slag cement is obtained by grinding the clinkers with about 60% slag and resembles more or less in properties of Portland cement. It can be used for works economic considerations is predominant.
8. High Alumina Cement
High alumina cement is obtained by melting mixture of bauxite and lime and grinding with the clinker. It is a rapid hardening cement with initial and final setting time of about 3.5 and 5 hours respectively.
The compressive strength of this cement is very high and more workable than ordinary portland cement and is used in works where concrete is subjected to high temperatures, frost, and acidic action.
9. White Cement
It is prepared from raw materials free from Iron oxide and is a type of ordinary portland cement which is white in color. It is costlier and is used for architectural purposes such as precast curtain wall and facing panels, terrazzo surface etc. and for interior and exterior decorative work like external renderings of buildings, facing slabs, floorings, ornamental concrete products, paths of gardens, swimming pools etc.
10. Colored cement
It is produced by mixing 5- 10% mineral pigments with ordinary cement. They are widely used for decorative works in floors.
11. Air Entraining Cement
Air entraining cement is produced by adding indigenous air entraining agents such as resins, glues, sodium salts of sulphates etc. during the grinding of clinker.
This type of cement is especially suited to improve the workability with smaller water cement ratio and to improve frost resistance of concrete.
12. Expansive Cement
Expansive cement expands slightly with time and does not shrink during and after the time of hardening . This cement is mainly used for grouting anchor bolts and prestressed concrete ducts.
13. Hydrographic cement
Hydrographic cement is prepared by mixing water repelling chemicals and has high workability and strength. It has the property of repelling water and is unaffected during monsoon or rains. Hydrophobic cement is mainly used for the construction of water structures such dams, water tanks, spillways, water retaining structures etc.
Concrete, usually Portland cement concrete, is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens over time—most frequently a lime-based cement binder, such as Portland cement, but sometimes with other hydraulic cements, such as a calcium aluminate cement. It is distinguished from other, non-cementitious types of concrete all binding some form of aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces, and polymer concretes that use polymers as a binder.
When aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix that binds the materials together into a durable stone-like material that has many uses. Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials (such as rebar) embedded to provide tensile strength, yielding reinforced concrete.
Famous concrete structures include the Hoover Dam, the Panama Canal and the Roman Pantheon. The earliest large-scale users of concrete technology were the ancient Romans, and concrete was widely used in the Roman Empire. The Colosseum in Rome was built largely of concrete, and the concrete dome of the Pantheon is the world’s largest unreinforced concrete dome. Today, large concrete structures (for example, dams and multi-story car parks) are usually made with reinforced concrete.
After the Roman Empire collapsed, use of concrete became rare until the technology was redeveloped in the mid-18th century. Worldwide, concrete has overtaken steel in tonnage of material used.