Putting forth effort on analyzing the action of turbulent flow on the sand particles on rvier bed surface,in this paper, the interdependent relation between the size distribution of coarse sand bed load and flow stren...Putting forth effort on analyzing the action of turbulent flow on the sand particles on rvier bed surface,in this paper, the interdependent relation between the size distribution of coarse sand bed load and flow strength is studied.A theoretical calculation formula obtained gives good results in accordance with the field data.展开更多
Recycled ceramic mixed sand（RCMS） was obtained by partially replacing ultra-fine sand with recycled ceramic coarse sand（RCCS）. The effects of RCCS replacement rate on the apparent density, workability, compressive...Recycled ceramic mixed sand（RCMS） was obtained by partially replacing ultra-fine sand with recycled ceramic coarse sand（RCCS）. The effects of RCCS replacement rate on the apparent density, workability, compressive strength and splitting tensile strength of recycled ceramic concrete（RCC） were investigated. In addition, the relationship between the water-cement ratio and compressive strength of RCC was also studied. The experimental results indicate that the reusing of recycled ceramic aggregate can improve the cohesiveness and water retentiveness of fresh concrete and benefit the mechanical properties development. When the RCCS replacement rate is not less than 40%, the mechanical properties of RCC are superior to those of the reference concrete. Moreover, when recycled ceramic medium sand was completely used as fine aggregate, the maximum increase in both compressive strength and splitting tensile strength were obtained, comparing with those of reference concrete, the increment ratio was 19.85% and 32.73%, respectively. The microscopic analysis shows that the using of recycled ceramic aggregate can meliorate distinctly the structure of the interfacial transition zone（ITZ） and increase the compaction degree of cement paste. Furthermore, an expression of the compressive strength of RCC and the cement-water ratio is regressed and gains a good linear relativity. It is an effective way to recycle waste ceramic, and the consumption of recycled ceramic aggregate could reach from 26.9% to 47.6% of the total weight of aggregate in producing concrete.展开更多
The compressive stress-strain behavior and other characteristics of treated fly ash based roof tiles have been studied by several experimental tests. This paper attempts to presents the results and observations of a s...The compressive stress-strain behavior and other characteristics of treated fly ash based roof tiles have been studied by several experimental tests. This paper attempts to presents the results and observations of a study and comparison based on the past reported experimental data. Based on the results and observations of the comprehensive experimental study, five “control points” have been identified. The new sets of experiment have been carried out to investigate whether it might be possible the use of fly ash in fly ash based roof tiles for residential construction. In the present study, treated fly ash (TFA) of C category was used with different materials as a replacement of clay for making treated fly ash stone dust roof tiles (TFASDRT). Treated fly ash stone dust roof tiles (TFASDRT) were studied at varying percentages of cement, coarse sand, and radish stone dust (RSD) along with the constant percentage of waste polythene fibre (WPF). A research program was undertaken to evaluate the suitability of such test for assessing the properties of treated fly ash stone dust roof tiles (TFASDRT). The result of this study recommends that the fly ash based roof tiles provides a sustainable supplement to the traditional clay roof tiles, they increase the efficiency of traditional roof tiles and significantly help to reduce the environmental issues associated with the disposal of these waste materials.展开更多
文摘Putting forth effort on analyzing the action of turbulent flow on the sand particles on rvier bed surface,in this paper, the interdependent relation between the size distribution of coarse sand bed load and flow strength is studied.A theoretical calculation formula obtained gives good results in accordance with the field data.
基金Funded by the National Natural Science Foundation of China(No.50902107)the Fundamental Research Funds for the Central Universities(No.2013-YB-25)
文摘Recycled ceramic mixed sand（RCMS） was obtained by partially replacing ultra-fine sand with recycled ceramic coarse sand（RCCS）. The effects of RCCS replacement rate on the apparent density, workability, compressive strength and splitting tensile strength of recycled ceramic concrete（RCC） were investigated. In addition, the relationship between the water-cement ratio and compressive strength of RCC was also studied. The experimental results indicate that the reusing of recycled ceramic aggregate can improve the cohesiveness and water retentiveness of fresh concrete and benefit the mechanical properties development. When the RCCS replacement rate is not less than 40%, the mechanical properties of RCC are superior to those of the reference concrete. Moreover, when recycled ceramic medium sand was completely used as fine aggregate, the maximum increase in both compressive strength and splitting tensile strength were obtained, comparing with those of reference concrete, the increment ratio was 19.85% and 32.73%, respectively. The microscopic analysis shows that the using of recycled ceramic aggregate can meliorate distinctly the structure of the interfacial transition zone（ITZ） and increase the compaction degree of cement paste. Furthermore, an expression of the compressive strength of RCC and the cement-water ratio is regressed and gains a good linear relativity. It is an effective way to recycle waste ceramic, and the consumption of recycled ceramic aggregate could reach from 26.9% to 47.6% of the total weight of aggregate in producing concrete.
文摘The compressive stress-strain behavior and other characteristics of treated fly ash based roof tiles have been studied by several experimental tests. This paper attempts to presents the results and observations of a study and comparison based on the past reported experimental data. Based on the results and observations of the comprehensive experimental study, five “control points” have been identified. The new sets of experiment have been carried out to investigate whether it might be possible the use of fly ash in fly ash based roof tiles for residential construction. In the present study, treated fly ash (TFA) of C category was used with different materials as a replacement of clay for making treated fly ash stone dust roof tiles (TFASDRT). Treated fly ash stone dust roof tiles (TFASDRT) were studied at varying percentages of cement, coarse sand, and radish stone dust (RSD) along with the constant percentage of waste polythene fibre (WPF). A research program was undertaken to evaluate the suitability of such test for assessing the properties of treated fly ash stone dust roof tiles (TFASDRT). The result of this study recommends that the fly ash based roof tiles provides a sustainable supplement to the traditional clay roof tiles, they increase the efficiency of traditional roof tiles and significantly help to reduce the environmental issues associated with the disposal of these waste materials.
