Green and Sustainable Concrete – The Potential Utilization of Rice Husk Ash and Egg Shells

Concrete which is widely used material in the construction industry, has a carbon footprint. Approximately 10% of global Carbon Dioxide (CO2) gas is emitted during the production of cement which is vital ingredient of concrete. The increase in production of cement affects global warming and climate change. Therefore, many have attempts have been made to develop green and sustainable concrete by utilizing different waste materials. With the utilization of waste materials as cement replacement, the CO2 gas emissions can be reduced as well as resolve the environmental issues that the inhabitants face during the disposal of such waste materials. This paper reviews the potential and innovative utilization of Rice Husk Ash (RHA) and Eggshells as partial cement replacement to develop green concrete. RHA which is rich in silica and eggshells contain identical amount of calcium oxide as cement, when finely grinded and used together as partial cement replacement, can trigger a pozzolanic reaction, in which silica reacts with calcium oxide resulting in the formation of calcium silicates which are responsible for achieving higher strengths

Evaluation of chromium(VI) sorption efficiency of modified Amberlite XAD-4 resin

The present work deals with the removal of Cr(VI) from aqueous media by modified Amberlite XAD-4 (MAX-4) resin through the solid phase extraction method. Different parameters such as pH, dosage and temperature were optimized during the batch experiment. The experimental data were analyzed by Freundlich, Langmuir, Dubinin-Radushkevich (D-R) and Temkin equilibrium isotherms. Each characteristic parameter of isotherms was determined. The kinetic sorption experiments show that the sorption process follows pseudo second order kinetics. The sorption mechanism was investigated by Reichenberg (R-B) and Morris–Weber equations. From the thermodynamic parameters, it could be concluded that the sorption process is endothermic and spontaneous in nature. The interference and desorption studies were also performed. The results show that MAX-4 resin has the capability to remove Cr(VI) significantly from aqueous media even in the presence of interfering ions

Utilization of Rubber Powder of Waste Tyres in Foam Concrete

Foam concrete or light concrete has become increasingly recognizable in commercial and construction field. Foam concrete is not just light in its weight but also light in cost, as there is no coarse aggregate needed in its production. Application of foam concrete is limited due to the fact that it is not as strong as conventional concrete in terms of strength and rigidness. Therefore, this study is to investigate the potential of foam concrete incorporating with rubber powder of waste tire and admixture as an additive material to improve its strength and workability. Thus, the use of rubber powder in this study could enhance the strength by filling the voids in foam concrete. The amount of rubber powder added as additive in foam concrete is 0%, 5%, 10%, 15% and 20% respectively. The amount of plasticizers used is limited to less than 0.4% to the weight of cement. The mix design was set to achieve density of 1800kg/m3. The workability of foam concrete is decreasing as the percentage of rubber power was increasing. The foam concrete containing 5%of rubber powder has highest compressive strength with value of 20.6 MPa for 7 days water curing and 22.3 MPa for 28 days water curing. Significantly showing an increase of 1.7 MPa. The highest value of tensile strength for both air curing 7 and 28 days are 1.86 MPa and 1.97 MPa also held by 3% of rubber powder mix. As a conclusion the optimum rubber powder content to be used in foam concrete is 5% that gives the highest results in terms of workability and strength

Fatigue and Rutting Analysis of Asphaltic Pavement Using “KENLAYER” Software

Rutting and Fatigue are taken as main premature failures among all distresses, as these distresses have wide effect on performance of pavement. Sudden variation of heavy axle loaded vehicles, improper mix design and traditional design methodologies used in pavement design industries are major factors behind these failures. For proper performance and good serviceability, these premature distresses should be resisted. Thus, there is a need of using a Mechanistic based design methodology like KENPAVE software, so that traditional design errors should be overcome. KENLAYER is a part of KENPAVE software. KENLYER software tool is utilized to calculated accurately stresses and strains in asphaltic pavement that are ultimately used in calculating allowance for rutting and fatigue failure utilizing Asphalt Institute design models or formulas. Resistance to Rutting failure is checked by calculating vertical compressive stress at the top of soil sub-grade layer, while resistance to fatigue failure is checked by calculating horizontal tensile strain at the bottom of asphaltic layer using KENLAYER software tool. Thus, the object of this research study is to analyze a flexible pavement with respect to rutting and fatigue distresses using KENLAYER software tool. For achieving that objective NHA (N-55) section of road in Sehwan Pakistan was taken as a reference pavement. Pavement was analyzed by altering the thicknesses of bituminous courses by ± 25 percent. From that we obtained total 20 cross-sections to be analyzed using KENLAYER software in terms of Rutting and Fatigue premature failures

Implementation of building information modeling (BIM) in Pakistan construction industry

This paper examines the implementation of building information modeling (BIM) in construction industry. Various initiatives and approaches are used in different countries to promote the BIM implementation in their construction industries. The real implementation and use of BIM remains a major concern of the construction industry. This study investigates the implantation of BIM globally, in developed countries and the percentage of implementation of BIM in constriction industry of Sindh, Pakistan. This research demonstrates 131 responses from BIM users regarding BIM implementation whose collaboration aspects produce the highest positive impact. The adopted methodology is an online questionnaire survey and literature review which was conducted to find out the implementation of BIM in construction industries of developed countries. This research reveals that BIM implementation is increasing continuously over the past few years. A Number of developed countries are emerging successful BIM implementation strategies, United States, United Kingdom, Germany, France are generally leading the way. However, according to our study findings, only 11% of industries have implemented BIM in Sindh, Pakistan

Significant mitigation measures for critical factors of cost overrun in highway projects of Pakistan

Stakeholders of the construction industry and academia are often facing problems of cost overrun. It has been observed that many constructions of highway projects are not completed at the approved cost due to certain factors. The objective of this research is to identify the cost overrun critical factors involved in highway projects with their significant mitigation measures. In this regard, literature review helped to identify 64 factors of cost overrun. Based on these 64 common factors, a preliminary survey was carried out among 30 selected respondents of highway projects to identify the critical factors of cost overrun and its possible mitigation measures. Results of the preliminary study reported 8 critical factors and 42 possible mitigation measures for the identified factors. Another questionnaire was established on the findings of the preliminary survey and was distributed among 350 stakeholders of highway projects to identify the significant mitigation measures of finding critical factors of cost overrun. In total, 8 significant mitigation measures were identified as causative and critical factors of cost overrun. The findings of this research would be helpful for the construction practitioners who are dealing with cost overrun issues in the highway projects of Pakistan