在不同膨胀剂掺入量下大体积混凝土膨胀后浇带内部应变变化试验研究  

Internal strain change of expansive post-poured strip with the different expansion agent quantity added in the mass concrete

作　　者：战永亮[1] 王鸿凯[1] 黄思凝[1] 黄红喜 程飞[2] 包研 

机构地区：[1]中国石油大学(华东),山东青岛266580 [2]中建八局一公司,山东济南250100

出　　处：《混凝土》2016年第9期128-131,共4页Concrete

基　　金：山东省优秀中青年科学家科研奖励基金(2014BSE28027);国家自然科学基金(51308510);中建八局科研开发立项项目中央高校基本科研业务费专项资金资助(15CX02055A)

摘　　要：为研究在不同膨胀剂掺量下大体积混凝土内部应变变化情况,在室内进行了原材料缩尺试验模拟,观察大体积膨胀混凝土在凝结硬化过程中,内部温差、干缩等"变形荷载"引起的混凝土内部应变变化规律,通过调节膨胀剂掺入量控制其变化结果,防止大体积混凝土早期裂缝产生。试验结果表明:4%膨胀剂掺入量下的混凝土早期拉应变接近其极限拉应变,此时混凝土内部可能产生裂缝;而膨胀剂掺入量超过9%时,预压应变增加并不明显,造成材料浪费;故膨胀剂掺入量为9%时控制效果最佳。In order to study the change of internal strain of large volume concrete under different expansive agents,the raw material scale test was conducted in the room.In the process of setting and hardening of the mass concrete,the concrete internal strain variation,caused by ＂deformation loads＂ of internal temperature and dry shrinkage was observed.Through adjusting the content of the expansion agents and controlling the change of the results,the early cracks in mass concrete were prevented.Test results illustrate the early tensile strain of concrete under 4% expansive admixture is close to its ultimate tensile strain,at this time the concrete internal may produce cracks.While the content of the expansion agent is more than 9%,the increase of the pre pressure strain is not obvious,and causes material losses.Therefore,when the content of the expansion agent is 9%,the control effect is the best.Therefore,when the content of the expansion agent is 9%,the control effect is the best.

关 键 词：大体积混凝土 补偿混凝土 膨胀剂 裂缝 膨胀后浇带 

分 类 号：TU528.55[建筑科学—建筑技术科学]