Based on the erosion resistant coefficient,the effects of water-cement ratio,air-entrained,silica fume content and sand ratio on the sulfate attack resistance of air-entrained silica fume concrete were studied by orth...Based on the erosion resistant coefficient,the effects of water-cement ratio,air-entrained,silica fume content and sand ratio on the sulfate attack resistance of air-entrained silica fume concrete were studied by orthogonal experiments in order to explore its sulfate attack resistance under dry-wet condition.A more significant model of concrete resistance to sulfate attack was also established,thus this work provided a strategy reference for quantitative design of sulfate attack resistant concrete.The experimental results show that dry-wet cycle deteriorates the concrete resistance to the sulfate attack,and leads to the remarkable declines of concrete strength and sulfate resistance.Air bubbles in the air-entrained silica fume concrete lower and delay the damage resulted from the crystallization sulfate salt.However this delay gradually disappears when most of the close bubbles are breached by the alternative running of the sulfate salt crystallization and the permeating pressure,and then the air bubbles are filled with sulfate salt crystallization.The concrete is provided with the strongest sulfate resistance when it is prepared with the 0.47 water-binder ratio,6.0% air-entrained,5% silica fume and 30% sand ratio.The erosion resistant coefficients K80 and K150 of this concrete are increased by 9%,7%,9%,and 5% respectively as compared with those of concretes without silica fume and air entraining.展开更多
The mechanical property of a novel expanded polystyrene cement-based material （EPS-C）, which was prepared by compressing semi-dry materials molding, was investigated. The compressive behavior was analyzed by compres...The mechanical property of a novel expanded polystyrene cement-based material （EPS-C）, which was prepared by compressing semi-dry materials molding, was investigated. The compressive behavior was analyzed by compression tests to gain the energy absorbed during failure. Performance for impact resistance was tested by a self-made device. The results figures out that the EPS-C has good toughness and can reach swain of 0.7 without failure. The stress-strain curve is quite different from that of normal EPS concrete. It can be divided into three stages and in the third stage the compressing exhibits the highest energy absorption. With the rising of cement ratio, the impact force absorption （IEA） decreases first and then increases. The impact energy absorption （IEA） increases first and then decreases. The lowest IEA and the highest lEA appear at the cement dosage from 233 g/L to 267 g/L and from 233 g/L to 300 g/L, respectively.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51168041 and 51578412)the Fundamental Research Funds for the Central Universities and the Key Laboratory of Advanced Civil Engineering Materials(Tongji University),Ministry of Education
文摘Based on the erosion resistant coefficient,the effects of water-cement ratio,air-entrained,silica fume content and sand ratio on the sulfate attack resistance of air-entrained silica fume concrete were studied by orthogonal experiments in order to explore its sulfate attack resistance under dry-wet condition.A more significant model of concrete resistance to sulfate attack was also established,thus this work provided a strategy reference for quantitative design of sulfate attack resistant concrete.The experimental results show that dry-wet cycle deteriorates the concrete resistance to the sulfate attack,and leads to the remarkable declines of concrete strength and sulfate resistance.Air bubbles in the air-entrained silica fume concrete lower and delay the damage resulted from the crystallization sulfate salt.However this delay gradually disappears when most of the close bubbles are breached by the alternative running of the sulfate salt crystallization and the permeating pressure,and then the air bubbles are filled with sulfate salt crystallization.The concrete is provided with the strongest sulfate resistance when it is prepared with the 0.47 water-binder ratio,6.0% air-entrained,5% silica fume and 30% sand ratio.The erosion resistant coefficients K80 and K150 of this concrete are increased by 9%,7%,9%,and 5% respectively as compared with those of concretes without silica fume and air entraining.
基金Funded by the Kwang-Hua Fund for College of Civil Engineering,Tongji Universitythe National Natural Science Fundation of China(No.41002093)the National Science and Technology Support Project of China(No.2012BAK24B04)
文摘The mechanical property of a novel expanded polystyrene cement-based material （EPS-C）, which was prepared by compressing semi-dry materials molding, was investigated. The compressive behavior was analyzed by compression tests to gain the energy absorbed during failure. Performance for impact resistance was tested by a self-made device. The results figures out that the EPS-C has good toughness and can reach swain of 0.7 without failure. The stress-strain curve is quite different from that of normal EPS concrete. It can be divided into three stages and in the third stage the compressing exhibits the highest energy absorption. With the rising of cement ratio, the impact force absorption （IEA） decreases first and then increases. The impact energy absorption （IEA） increases first and then decreases. The lowest IEA and the highest lEA appear at the cement dosage from 233 g/L to 267 g/L and from 233 g/L to 300 g/L, respectively.
