The enhancement of interface bonding between cement and polymerand the structural reticula-tion of the water-soluble polymer areproposed to minimize the shortening of the mechanical properties ofmacro-de-fect-free(MDF...The enhancement of interface bonding between cement and polymerand the structural reticula-tion of the water-soluble polymer areproposed to minimize the shortening of the mechanical properties ofmacro-de-fect-free(MDF)cement based composites at high relativehumidity.The MDF composites incorporated with vari-ouscross-coupling agents studied experimentally.The results show thatthe MDF composites modified with small amounts of cross-couplingagent had raised mechanical properties,but it is more important thatthe modified MDF composites had a significant increase in waterresistance compared to the original one.展开更多
Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched pris...Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.展开更多
文摘The enhancement of interface bonding between cement and polymerand the structural reticula-tion of the water-soluble polymer areproposed to minimize the shortening of the mechanical properties ofmacro-de-fect-free(MDF)cement based composites at high relativehumidity.The MDF composites incorporated with vari-ouscross-coupling agents studied experimentally.The results show thatthe MDF composites modified with small amounts of cross-couplingagent had raised mechanical properties,but it is more important thatthe modified MDF composites had a significant increase in waterresistance compared to the original one.
文摘Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.
