轻细骨料内养护混凝土抗压强度与模拟  

Compressive strength of internal curing concrete with lightweight fine aggregate-experiment and modeling

作　　者：向亚平[1,2] 魏亚[2] 张倩倩[2] 王栋民[1] 

机构地区：[1]中国矿业大学(北京),北京100083 [2]清华大学土木工程系,北京100084

出　　处：《混凝土》2013年第3期44-47,51,共5页Concrete

基　　金：高等学校博士学科点专项科研基金资助课题(20110002120010)

摘　　要：研究了2种饱水轻细骨料（粉煤灰陶砂和页岩陶砂）各自等体积取代不同普通砂时对水灰比0.3和0．4混凝土28d抗压强度影响。试验表明：取代砂体积为0-60％时，随着轻细骨料掺量增加，水灰比0_3两种轻细骨料混凝土28d抗压强度都高于普通混凝土，且都在40％时达到最高；取代砂体积0-40％时，水灰比0．4两种轻细骨料混凝土28d抗压强度随轻骨料掺量增加而减小。当水灰比和取代砂体积相同时，掺粉煤灰陶砂混凝土28d抗压强度都要高于掺页岩陶砂混凝土。对含有轻细骨料混凝土的抗压强度进行理论模拟，为此提出了混凝土中轻骨料体积-孔隙率转换系数．γ（0．1），结合强度孔隙率模型、Powers模型和内养护浆体模型计算了轻细骨料内养护混凝土28d抗压强度，模拟结果与试验值较为吻合。Two types of saturated lightweight fine aggregates （blast furnace slag and shale sand） were used to substitute the equivalent volume of regular fine aggregates in the concrete specimens（with W/C ratio of 0.3 and 0.4 ）.The influence on 28 d compressive strength due to the replacement of regular fine aggregates by these lightweight fine aggregates was investigated.Experimental evidence showed that when there was 0-60% volume of fine aggregate replaced, at 0.3 W/C ratio ,the concrete samples with lightweight fine aggregates would exhibit higher 28 d compressive strength than normal concrete.When 0-40% of fine aggregate was substituted by lightweight fine aggregates, for W/C=0.4, the specimens＇ 28 d compressive strength decreases as the proportion of fine aggregate increases.When the volume fraction of the replacement fine aggregate and the W/C were equal,the blast-furnace-slag-blend concrete specimens were stronger in compressive than their shale counterparts.It attempted to model the compressive strength of lightweight-fine-aggregate concrete.A parameter- lightweight fine aggregate volume-to-porosity conversion coefficient γ（0-1） was introduced.The Strength-porosity relationship,Powers model, internal curing paste volume model were incorporated in this model prediction of the 28 d compressive strength of the specimens. The test results and the model predictions have shown good agreement.

关 键 词：轻细骨料 混凝土 内养护 抗压强度模拟 

分 类 号：TU528.01[建筑科学—建筑技术科学]