The traditional construction system separates the two main disciplines of construction, namely design and construction. The consultant (design engineer) is in charge of the design, whereas the contractor is in charge of the construction. It is uncommon to see both sides communicate prior to the commencement of construction. The designers who are developing the design have no prior building experience. This keeps them in the dark and forces them to consider designs that are more in line with the practical implications. As a result, the design becomes more complex, the cost exceeds expectations, and the project takes longer to complete. As a result, construction expertise must be incorporated into the design process. To aid the design engineer in comprehending the constructability of a chosen design.
Importance of Constructability in Design Phase of Construction
Buildability is another synonym for constructability, which is a new term in the building business. However, the concept of constructability has existed in the past. The conventional separation of construction and design has resulted in less efficient performance on construction projects, according to the constructability study.It also demonstrates that the designer and the contractor in charge are equally responsible for achieving constructability. This new word is generating a lot of buzz among construction professionals. Constructability planning allows for the best possible integration of construction knowledge and expertise with the engineer’s design. This aids in the achievement of the project’s overall goals. However, there are still issues with how formally we can implement constructability in practise.
Design Details and Constructability
In the design stage of the project, important design factors such as approaches for easy design construction and functionality are critical. Both the functional and constructional components of detailing influence the overall performance of a construction endeavour. Consider a project involving the construction of an external wall. The fundamental needs are to provide overall aesthetic appeal, energy, durability, fire resistance, acoustical and structural strength. Compatibility with adjacent components, installation, cost, and time are all critical considerations in addition to the previously mentioned concerns. Other than aesthetics and functionality, we need to concentrate on construction-related concerns such as feasibility, cost, and timetable.
The need of including constructability into the design process is sometimes overlooked. During the project’s construction, this will pose issues with project disruption. This could potentially lead to legal issues. This will serve as a reminder to bring up simple construction facilities in terms of design elements. Constructability is more important for site plans, project plans, and significant building projects. Data gathering and good documentation are required for constructability improvement. The constructability factor is a significant component that aids in the development of a systematic strategy to assessing and cataloguing building aspects. Computer technology can be used to capture and code the experiences from the field.
View point of Contractor
According to the interviews done with several of the contractors, the majority of the contractors have no issues regarding the design concept. However, I am having difficulties with the design’s details. This is due to the difficulty of implementing design details in practise. The issues encountered are listed below:
1. Time and money are spent on purchasing complex designs.
2. The provided information could be of poor quality. The examination of the site as well as the construction blueprints are included in the data.
3. The designs are presented without regard for their practicality. The entire effect that the design will provide is not taken into account.
4. Economic designs are more expensive due to complex shapes or construction processes.
The majority of the drawings are not adequate for site operations, according to the results of the survey study. Drawings of poor quality are frequently chastised for their lack of clarity and crucial material.The problems are explained using the following examples: A lack of coordination, as well as conflicting information, results in contradictory information. This information comes from a variety of sources, including architects, engineers, mechanical, and electrical experts. The information is lacking. The lead designer completes some aspects of the design before handing it over to the contractor to finish.
The difficulties faced in the foundation design are
The contractor’s working method is not taken into account during the design stage. This is mostly in the details of the excavations, such as site stripping. Instead of excavating various regions in isolation, this is done in a single operation to reach the decreased level. The use of small quantities of materials at the expense of extra plant time and labour is another issue. For example, if the pad foundations are close together, excavating each one separately is not economically effective. It is preferable to excavate a strip foundation to the required decreased level in a single operation.The challenges of designing structural frames.
1. There is a mishmash of trades within structural elements, as well as an inefficient sequence of operations. 2. When carrying out the detail design of the structural frame, the designers in charge pay no or very little attention to the speed of erection. This includes designing and constructing an in-situ staircase as well as making accommodations for gaps in structural elements. 3. When it comes to making holes in concrete walls, there are a few issues to consider. These are some of them:o Reinforcement will be more difficult to install.o Fixing the boxed-out parts to the formwork takes more time and money. Poor finish and completion difficulties while enduring concrete compaction under a square box-out.
The difficulties faced in reinforcement design
The requirement for greater prefabrication will complicate the reinforcing design. When it comes to steel reinforcement for slab and beam flooring, prefabrication is favoured. The ground level is where the beam cages are positioned. After that, the arrangement is lifted and set in the desired location. While prefabricating the reinforcement, it is critical to give adequate cover, particularly end covers. There is no such thing as a good prefabricated cage if there aren’t enough covers.The problems encountered in the design of Formwork
1. The reuse and repetitive use of formwork designs is the main challenge. The majority of lift shafts are constructed as bracing by the designers. It is vital to select a temporary work designer throughout the construction of the project.
2. Another issue is that the design does not take advantage of mechanisation to its full potential. This measure may assist in lowering labour costs.
3. More complicated shapes are presented. This is purchased under the false assumption that the least amount of material is used, resulting in the lowest cost. The difficulties in practise is not taken into account.
Most of the major constructability challenges should have already been incorporated into the construction plans as the project gets underway. A constructability review follow-up action register is typically useful at this time to capture actions and responsibilities acquired from the formal constructability reviews that have been continuing throughout the planning and detailed design phases. As the project execution plan (PEP) proceeds, a project constructability coordinator should be in charge of working with each manager or supervisor to ensure that items are closed out and correctly documented. The project manager or his or her designate should be in charge of ensuring that lessons learned from constructability reviews are recorded and discussed with the project constructability coordinator so that they may be shared with other project teams. The constructability methodology promotes continuing learning in this way.
During the pre-construction phase, constructability (or buildability) is a project management technique for reviewing construction processes from start to end.
“Constructibility Review,” according to the AASHTO Subcommittee on Construction, is “a procedure that employs construction specialists with considerable construction knowledge early in the design stages of projects to guarantee that the projects are buildable, cost-effective, biddable, and maintainable.”
The integration of construction expertise and knowledge into the design phase or preconstruction of a project.