Most important problems arising from industrial and technological developments are abundance and harmful effects of post-productive wastes. In most of the developed countries, these effects are avoided by orderly stor...Most important problems arising from industrial and technological developments are abundance and harmful effects of post-productive wastes. In most of the developed countries, these effects are avoided by orderly storing methods. Storing the wastes in random stacks in the site, and their effect on wide areas gives a rise to the risk of ground, air and under water pollution e.g., pollution of the surrounding environments. Therefore, in most engineering branches, effects and nature of harmful wastes are investigated and solution methods are developed. When structures made of concrete are to be demolished. Concrete recycling is an increasingly common method of disposing of the rubble. Concrete debris was once routinely shipped to landfills for disposal, but recycling has a number of benefits that have been made it a more attractive option in this age of greater environmental awareness, more environmental lows, and the desire to keep constant costs down. The purpose of this research is to study the effect of using demolished concrete as a reproducible coarse aggregate in fabricating normal and high strength concrete mixes. The effect of constituent materials in general and the recycled coarse aggregate in particular on the mechanical performance of the produced concrete mixes is investigated. The characteristics of using the by-pass product of cement industry as cementitious material in recycled concrete mixes with a percentage of 50% as a replacement of cement content is investigated too. Test results presented in this research leads to the promising use of crushed demolished concrete along with the by-pass product of cement as waste materials in producing concrete mixes as well as the optimistic results in enhancing the strength properties of plain concrete beside their benefits of the cost savings and reducing environmental impact.展开更多
To enhance the performance of mix granulate road base courses by cement treatment. The mechanical properties of cement treated mix granulate （CTMG） were studied, which was designed with 65% crushed masonry and 35% c...To enhance the performance of mix granulate road base courses by cement treatment. The mechanical properties of cement treated mix granulate （CTMG） were studied, which was designed with 65% crushed masonry and 35% crushed concrete by mass. The central composite design was employed to prepare specimens with different levels of cement content and degree of compaction. All specimens were cured in a fog room at 20 ℃ for a specific number of days. The compressive strength and the indirect tensile strength were determined through the monotonic compression and indirect tension tests. Effective prediction models for the mechanical properties of CTMG, in relation to the cement content, the degree of compaction and the curing time, were successfully established for a mix containing 65% crushed masonry and 35% crushed concrete by mass.展开更多
文摘Most important problems arising from industrial and technological developments are abundance and harmful effects of post-productive wastes. In most of the developed countries, these effects are avoided by orderly storing methods. Storing the wastes in random stacks in the site, and their effect on wide areas gives a rise to the risk of ground, air and under water pollution e.g., pollution of the surrounding environments. Therefore, in most engineering branches, effects and nature of harmful wastes are investigated and solution methods are developed. When structures made of concrete are to be demolished. Concrete recycling is an increasingly common method of disposing of the rubble. Concrete debris was once routinely shipped to landfills for disposal, but recycling has a number of benefits that have been made it a more attractive option in this age of greater environmental awareness, more environmental lows, and the desire to keep constant costs down. The purpose of this research is to study the effect of using demolished concrete as a reproducible coarse aggregate in fabricating normal and high strength concrete mixes. The effect of constituent materials in general and the recycled coarse aggregate in particular on the mechanical performance of the produced concrete mixes is investigated. The characteristics of using the by-pass product of cement industry as cementitious material in recycled concrete mixes with a percentage of 50% as a replacement of cement content is investigated too. Test results presented in this research leads to the promising use of crushed demolished concrete along with the by-pass product of cement as waste materials in producing concrete mixes as well as the optimistic results in enhancing the strength properties of plain concrete beside their benefits of the cost savings and reducing environmental impact.
文摘To enhance the performance of mix granulate road base courses by cement treatment. The mechanical properties of cement treated mix granulate （CTMG） were studied, which was designed with 65% crushed masonry and 35% crushed concrete by mass. The central composite design was employed to prepare specimens with different levels of cement content and degree of compaction. All specimens were cured in a fog room at 20 ℃ for a specific number of days. The compressive strength and the indirect tensile strength were determined through the monotonic compression and indirect tension tests. Effective prediction models for the mechanical properties of CTMG, in relation to the cement content, the degree of compaction and the curing time, were successfully established for a mix containing 65% crushed masonry and 35% crushed concrete by mass.
