In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment accordin...In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.展开更多
Effect of isobutyl-triethoxy-silane penetrative protective agent on the carbonation resistance of the concrete was studied.The concrete specimens for the 28 d accelerated carbonation process were manufactured with w/c...Effect of isobutyl-triethoxy-silane penetrative protective agent on the carbonation resistance of the concrete was studied.The concrete specimens for the 28 d accelerated carbonation process were manufactured with w/c of 0.49 and 0.64,both in the presence and absence of silane and mineral admixture.The penetration of isobutyl-triethoxy-silane and the carbonation of concrete were investigated by penetration depth,carbonation depth,XRD,SEM,and pore size distribution.The results showed that concrete compactness played an important role in the silane penetration and carbonation resistance.Penetration depth of silane-treated concrete mainly depended on the compactness of the concrete,and could not remarkably change through the accelerated carbonation process.In the accelerated carbonation process,penetrative protective agent improved the carbonation resistance of the higher compactness concretes but accelerated the carbonization process of the lower compactness concretes.As penetrative protective agent penetrated along the external connectivity pores into concrete not filling the entire surface area,the inorganic film could not fully protect the Ca（OH）_2 phase from carbonation.After 28 d accelerated carbonation,fibrous hydration products disappeared and the surface holes decreased.Due to the formation of carbonized products,the porosity of the concrete surface decreased,especially in high-strength concrete.展开更多
文摘In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.
基金Funded by the National Sci-Tech Support Plan of China(No.2013BAJ10B05)Marine Interdisciplinary Research Guide Fund of Zhejiang University(No.2012HY003B)
文摘Effect of isobutyl-triethoxy-silane penetrative protective agent on the carbonation resistance of the concrete was studied.The concrete specimens for the 28 d accelerated carbonation process were manufactured with w/c of 0.49 and 0.64,both in the presence and absence of silane and mineral admixture.The penetration of isobutyl-triethoxy-silane and the carbonation of concrete were investigated by penetration depth,carbonation depth,XRD,SEM,and pore size distribution.The results showed that concrete compactness played an important role in the silane penetration and carbonation resistance.Penetration depth of silane-treated concrete mainly depended on the compactness of the concrete,and could not remarkably change through the accelerated carbonation process.In the accelerated carbonation process,penetrative protective agent improved the carbonation resistance of the higher compactness concretes but accelerated the carbonization process of the lower compactness concretes.As penetrative protective agent penetrated along the external connectivity pores into concrete not filling the entire surface area,the inorganic film could not fully protect the Ca（OH）_2 phase from carbonation.After 28 d accelerated carbonation,fibrous hydration products disappeared and the surface holes decreased.Due to the formation of carbonized products,the porosity of the concrete surface decreased,especially in high-strength concrete.
