Construction industry plays an important role in the development of a country. The success of any project will depends on how that project can achieve its objectives in terms of cost, quality and duration. In order to achieve success in a project, it would be essential to plan that project well and have a proper monitoring mechanism in place. Cost overrun is a major problem encountered by many contractors as it makes the profit of a project less secure for the contractor in addition to causing many other problems to all the parties involved. Good cost control techniques would be essential to solve those problems. Thus, it is important to identify cost controlling techniques and their impact on cost overruns. This study was done using a questionnaire survey conducted among C1-C5 grade contractors. The data collected were analysed by converting them into quantitative values using percentage analysis and weighted score analysis. The results indicate the cost controlling practices that are in frequent use and their importance in minimizing the cost overruns in order to reduce over budget and overheads while securing anticipated profits. Finally, it is suggested that CIDA (ICTAD) should encourage contractors to use cost controlling techniques, by conducting training programs, awareness programs, etc. It is also suggested to make the use of some of ICTAD documents mandatory.

The inherent nature of construction projects is long duration and high cost. Extended project duration leads to escalation of cost. If the project duration is too long, the initial estimation may not be sufficient to recover the actual cost of the contract. To address this problem, Construction Industry Development Authority (CIDA) has introduced a price adjustment method called the “ICTAD formula method for adjustments to contract price due to fluctuation in prices”. Contract documents related to construction projects also provide some provisions to address the issues with material price fluctuations. This study investigated the practices of contractors to minimize the effect of price variation and support of price fluctuation clauses to minimize the impact of price variation. A questionnaire survey was conducted among the professionals to represent CS2 to C5 grade construction companies registered at CIDA. The questionnaire consisted of practices of contractors to minimize the effect of price variation and the impact of using price fluctuation clauses in different aspects. Collected responses were converted to a quantitative value using the relative importance index (RII). In addition, SPSS software was used for the critical review of responses. The results revealed that contractors mostly agree with using price fluctuation clauses to recover the increased project cost due to increased construction input prices. Further, results are evident that using price fluctuation clauses helps to fair risk sharing between the contractor and the client.

This study evaluates the feasibility of using waste polyethylene as a construction material. To achieve this, a series of polymer composites were developed using waste Low-Density Polyethylene (LDPE) reinforced with coconut fiber (coir). The mechanical properties, including the tensile strength, flexural strength, impact strength, and elastic modulus, were assessed, along with the water absorption as a key physical property by following the ASTM standards. The composites were fabricated using the hand layup technique with varying coir-to-LDPE weight ratios and fiber lengths, followed by a hot-press machine manufacturing under controlled conditions. The results demonstrated that different fiber lengths and content levels influenced the mechanical properties, optimizing them at various configurations. A maximum tensile strength of 12.56 MPa was achieved using 40% coir content with 4 cm fiber length. The highest elastic modulus value of 0.46 GPa was achieved at 50% fiber content with 4 cm fibers. At 30% fiber content with 3 cm length, the maximum flexural strength value of 33.77 MPa was obtained. The impact strength reached its maximum value of 1.22 kJ/m² with 40% fiber content and 2 cm fiber length. The high water absorption exhibited by the composites, can be mitigated by applying waterproofing chemicals immediately after fabrication. It was found that the integration of fiber content and length affects the composite's properties. Depending on the required characteristics, appropriate fiber lengths and mix proportions can be selected, making these composites suitable for various applications in the construction industry. Additionally, proper waterproofing immediately after manufacturing the composite is proposed to enhance its performance as a construction material.

The use of the earth as a building material has been practiced since the beginning of human civilization. Unburnt bricks, rammed earth, adobe, and burnt bricks are some of them. As a result of technological development, adobe has developed into a compressed stabilized earth block (CSEB). The clay percentage of the soil significantly affects the strength of the CSEB. This study focused on controlling the clay percentage by adding larger particles externally using building construction waste and reinforcing them with coconut coir. Different coir amounts by weight from 0.1% to 0.5% with different lengths of 2 cm, 4 cm, 6 cm, and 8 cm were considered for block production. For dry compressive strength and wet compressive strength, the combination of 0.3% coir amount with 6 cm coir length gave the maximum strength, and it also satisfied the required water absorption limit as per the Grade 1 category of the SLS 1382, part 1. After that, using the above combination, the industrial scale (350 × 100 ×175) mm size block was prepared, and its strength also satisfied the SLS 1382 Grade 1 requirements. According to the study, the manufacturing cost for the CSEB is lower than that of cement blocks and clay bricks. The cost for a 1 m2 wall panel preparation using CSEB is 41.52% lower than preparing using burnt clay brick and 8.56% lower than preparing using cement blocks. Therefore, the CSEB can be used as a load-bearing walling material at a low cost and with eco-friendliness.

Environmental concerns and economic crises have been more critical in recent years, making it impossible to continue construction using traditional resources (cement, sand, and natural aggregates) in the same way as before. However, the use of earth is a cost-effective solution and it can enhance the sustainability of construction materials by employing soil as a building material. This study evaluated soil consistency that would be acceptable to make soil concrete and analysed the effect of chemical admixtures in achieving the maximum possible strength. Hence, the study suggested the possibility of using soil to form concrete as a replacement for cement concrete to the maximum extent with self-compacting properties. The soil was used to produce the concrete, stabilizing with cement and chemical admixtures were used to improve the strength and workability. According to the experimental investigation, it can be concluded that soil can be used as concrete with a characteristic strength of 15 MPa. The recommended native soil consistency for soil concrete should be developed by rearranging the native soil gradation to 5%–10% fines, 55%–71% sand, and 24%–40% gravel. The recommended cement amount as the stabilizer is 16% to 18% of the weight of the improved dry soil mixture. The strength and workability can be further improved by employing suitable chemical admixtures. Finally, this extensive study concluded that soil could be used to produce concrete for the construction industry through applications with minor improvements to the existing soil.