The incorporation of waste materials generated in many industries has been actively advocated for in the construction industry, since they have the capacity to lessen the pollution on dumpsites, mitigate environmental resource consumption, and establish a sustainable environment. This research has been conducted to determine the influence of different rice husk ash (RHA) concentrations on the fresh and mechanical properties of high-strength concrete. RHA was employed to partially replace the cement at 5%, 10%, 15%, and 20% by weight. Fresh properties, such as slump, compacting factor, density, and surface absorption, were determined. In contrast, its mechanical properties, such as compressive strength, splitting tensile strength and flexural strength, were assessed after 7, 28, and 60 days. In addition, the microstructural evaluation, initial surface absorption test, = environmental impact, and cost–benefit analysis were evaluated. The results show that the incorporation of RHA reduces the workability of fresh mixes, while enhancing their compressive, splitting, and flexural strength up to 7.16%, 7.03%, and 3.82%, respectively. Moreover, incorporating 10% of RHA provides the highest compressive strength, splitting tensile, and flexural strength, with an improved initial surface absorption and microstructural evaluation and greater eco-strength efficiencies. Finally, a relatively lower CO₂-eq (equivalent to kg CO₂) per MPa for RHA concrete indicates the significant positive impact due to the reduced Global Warming Potential (GWP). Thus, the current findings demonstrated that RHA can be used in the concrete industry as a possible revenue source for developing sustainable concretes with high performance.

The utilization of waste fly ash and natural jute fiber has drawn attention to producing sustainable concrete. However, there is a lack of studies to analyze the synergistic effect of jute fiber and fly ash on the properties of concrete. Hence, the aim of this study is to investigate the combined effect of fly ash concentration and the different sizes of jute fiber on the fresh, hardened, and non-destructive testing properties of concrete. Concerning the purpose, the concrete mixes were prepared with 0.2 % and 0.4 % jute fiber incorporating 0 %, 5 %, 10 %, and 15 % replacement of cement by fly ash in concrete. For the assessment of properties, slump, density, and compacting factor test was conducted at the fresh state of concrete, whereas mechanical properties such as compressive, splitting tensile, and flexure strength test were conducted at 7 and 28 days. In addition, the non-destructive test (NDT) was also carried out to predict the destructive compressive strength by rebound hammer at 28 days. The microstructure property of optimum mix concrete was analyzed by scanning electron microscopy (SEM). It is observed that the incorporation of jute fiber decreased the slump, density, and compacting factor but increased the compressive, splitting tensile, and flexure strength, whereas the fly ash improved both fresh and hardened properties. Compared to the standard mix, fly ash-based JFRC mixtures have compressive strength improvements varying from 1.7 % to 25.9 %. The 10 % fly ash and 0.2 % volume of jute fiber exhibited a maximum of 11.64 % and 10.72 % splitting tensile and flexural strength enhancement at 28 days, respecting the control mix. In addition, the NDT strength assessment obtained 5.5 % less than destructive strength on average. From the SEM point of view, it is obtained that the 10 % fly ash with 0.2 % jute fiber composition matrix exhibits a better bonding interface and the cracking resistance nature of the concrete mix.

This research work is devoted to the experimental investigation of both rheological and mechanical properties of self-compacting concrete (SCC) produced with waste galvanized copper wire fiber and rice husk ash (RHA). In the study, three different volume fractions of 0.5 p to 0.75 percent, 1 percent of scrap copper wire fiber as reinforcing material, and 2 percent RHA as cement replacement were used. To evaluate the fresh characteristics of SCC, the slump flow, J-ring, and V-funnel experiments were conducted for this investigation. Compressive strength, splitting tensile strength, and flexural strength of the concrete were conducted to assess the hardened properties. The test was carried out to compare each characteristic of plain SCC with this modified SCC mixture, containing RHA as pozzolanic materials and copper fiber as reinforcing material. Incorporating copper fiber in the SCC leads to a drop in fresh properties compared to plain SCC but remains within an acceptable range. On the other hand, the inclusion of 2% RHA makes the SCC more viscous. Although adding 2% RHA and 1% copper wire in SCC provide the highest strength, this mix has an unacceptable passing ability. The SCC mix prepared with 2% RHA and 0.75% copper fiber is suggested to be optimum in terms of the overall performance. According to this study, adding metallic fiber reinforcement like copper wire and mineral admixture like RHA can improve the mechanical properties of SCC up to a certain level.

Fiber-reinforced polymer (FRP) is a revolutionary breakthrough in the history of structural engineering innovation due to its unique characteristics to strengthen and repair the deficient reinforced concrete structures. This paper aimed at evaluating the flexural characteristics of jute fiber reinforced polymer (JFRP) bonded reinforced concrete beams. The influence of the test variables comprised of strengthening scheme and corrosion rate for reinforced concrete (RC) beams. The experimental study comprised of casting six RC beams and testing them in flexure loading. To determine the flexural response of RC beams, three beams were fabricated with JFRP laminate having a level of corrosion of 0%, 7.5%, and 15%, whereas three beams were designated as control beams having same corrosion levels with no JFRP. Test results indicated that all JFRP strengthened beams exhibited increased ultimate load, yield load, first cracking load, and lower ductility index compared to control beams. The results also revealed that JFRP strengthening technique improved the flexural strength of the corroded beams efficiently, albeit the ultimate load of the beams diminished with higher corrosion level. Analytical calculations were carried out for quantifying the flexural characteristics and mass loss of beams which provided a good agreement with the test results.

This study aims to investigate the combined influence of varying concentration of waste steel fibre and fly ash on rheological and mechanical performance of fibre-reinforced concrete (FRC). Cement was substituted partially by fly ash at concentration of 5%, 10% and 20% by weight basis and waste steel fibre was incorporated as 1.5% and 3% in volume basis of concrete. Rheological tests of concrete, including slump, density, compacting factor, K-slump, and Kelly ball penetration were evaluated for the fresh state. Mechanical performances of concrete, including compressive, splitting tensile and flexural strength were determined at 7 and 28 days. Test results exhibited that fly ash enhanced the workability of all rheological tests; however, waste steel fibre reduced the workability and increased the density of fresh concrete. Substantial enhancement in compressive, splitting tensile and flexural strength was found for fly ash and waste steel FRC mixes than the control one. The optimum results of mechanical performance were achieved for mixture with concentration of 10% fly ash and 3% waste steel fibre among all mixes. Adding waste steel fibre with fly ash in concrete provided more pronounced mechanical performance at higher fibre concentration along with the minimisation of disposal problems and environmental damages.

Purpose: This paper aims to identify the critical project management success factors and analyze those factors to achieve a sustainable construction industry in Bangladesh. Design/methodology/approach: This study identified 41 major problematic factors from the related literature. In this research, a detailed questionnaire survey was conducted among the experts and stakeholders of the construction industry of Bangladesh. The survey was carried out on a Likert scale and ranked the critical factors using the relative importance index (RII). The 41 problematic factors were divided into five group factors and ranked by the RII index to prioritize the factors. Finally, stakeholders' opinions were analyzed with the critical assessed factors, which was a very effective technique to eliminate the risks and uncertain occurrences in the construction industry of Bangladesh. Findings: The factors analysis revealed that cost overrun, traffic jam, low wedges, slow payment for completed works and financial issues of the owner were leading critical factors in construction projects. Moreover, the critical factors are divided into five-factor groups, namely, financial management, monitoring and feedback, competency management, communication and coordination management, and risk management, which exhibit 0.767, 0.720, 0.711, 0.710 and 0.658 RII values. After all, the stakeholders' opinion suggested that implementing modern tools and techniques can help to avoid the critical situation in the construction industry of Bangladesh. Practical implications: The construction industry of Bangladesh is moving away from stable construction work day by day. Previously, the potential CSFs were discussed unstructured way. Hence, detecting early warning signals in a structured way has become necessary for the building firm's survival. Originality/value: Though some scattered critical issues are discussed in different literature, the critical issues of the Bangladeshi construction industry were not investigated extensively. Therefore, this study finds out the potential critical issues of the construction industry of Bangladesh to accumulate such harmful construction issues in a single platform so that the construction industry can have an overview of them with the help of innovative technologies.