Influence of fine aggregate type on mechanical properties and pore structure of concrete
Concrete with different water-cement ratios was prepared using machine-made sand,aeolian sand,and river sand,and the compressive,axial compressive,splitting tensile,flexural,bond strength and slump tests were carried out.The influence of different fine aggregates on concrete per-formance was clarified by examining changes in the microscopic pore structure.The test results show that the manufactured sand enhances the compressive strength,bond strength,tensile deformation ca-pacity,and toughness of concrete,while the aeolian sand reduces the mechanical properties of con-crete.With the increase of water-binder ratio and water-reducing agent content,the mechanical proper-ties of concrete with different fine aggregates decrease to varying degrees.Compared with ordinary river sand concrete,the mechanical properties of aeolian sand and machine-made sand concrete decrease to a lesser extent.Machine-made sand and aeolian sand reduce the interference between aggregates,in-crease the fine aggregate filling rate and the proportion of open pores,making the concrete more dense and strengthening the pore structure,but both of them increase the proportion of macropores in the con-crete.Both machine-made sand and aeolian sand significantly reduce the working performance of con-crete.With the increase of water-cement ratio and water reducing agent content,the slump increases significantly.However,when the water-cement ratio and water-reducing agent content are too large,the setting and hardening time of aeolian sand concrete is prolonged by about 3 times,and the interior is in a moist and weakly adhesive state.
fine aggregateconcretemechanical propertiesworking performancefilling ratepore structure
万方数据
维普
