【摘要】 为减少泵送高强轻骨料混凝土在振捣过程中轻骨料的上浮现象,使用5种不同轻骨料,根据混凝土拌合物振捣后的上、下层拌合物密度差异和粗骨料质量差异计算分层度,作为评价拌合物抗振捣分离性指标,对比轻骨料混凝土与普通混凝土的抗离析性,并研究轻骨料体积含量、振捣时间和轻骨料特性(包括外形、表面光滑度、吸水率)对低水胶比的泵送高强轻骨料混凝土抗离析性的影响。结果表明,轻骨料混凝土与普通混凝土的抗离析性差异不大;轻骨料特性对抗离析性影响明显;采用表面多孔而粗糙、呈碎石形、含水率高的陶粒,减少粗骨料体积含量、减少振捣时间有助于减少分层度;振捣后拌合物上、下层粗骨料质量分层度可比较敏感地反映混凝土的抗离析性。更多还原

【Abstract】 To reduce the segregation of fresh High Strength Lightweight Aggregate Concrete(HSLWAC) in vibrating process,the vibrating-layering tests were carried out with 5 types of lightweight aggregates.The segregation capability is judged by the layering degree,the layering degree is calculated by the density difference and the coarse aggregate mass difference between roof and bottom.Investigated the factors of LWA’s volume quantity,vibrating time,and the characters of LWA (include external form,surface smooth level,water absorption) in the segregation of pumping HSLWAC with lower water to binder ratio.Compared with the normal concrete,the results showed that,the segregation theory of HSLWAC is similar to that of normal weight concrete;but the characters of LWA can affect the segregation capability observably;To reduce the segregation,porous,rubbly aggregates or that with rough surface,high water absorption can be used;also the quantity of coarse aggregate should be decreased or shortened the vibrating time;the coarse aggregate mass difference between roof and bottom can show the segregation capability sensitively.更多还原