非饱和粉土土模压实度对现浇混凝土强度影响研究  

Study on Influence of Compaction Degree of Unsaturated Silty Soil on the Strength of Cast-in-situ Concrete

作　　者：韩成国 Han Chengguo(China Railway 17^th Bureau Group 5^th Engineering Co.Ltd.,Taiyuan Shanxi 030032,China)

机构地区：[1]中铁十七局集团第五工程有限公司

出　　处：《铁道建筑技术》2019年第11期33-36,96,共5页Railway Construction Technology

基　　金：中铁十七局集团有限公司科技研究开发项目(2017-112)

摘　　要：“土模”作为传统模板施工工艺,不仅减少了混凝土模板的投入,节约经济成本,同时也降低了混凝土模板的周转使用周期,加快了工程施工进度.但土模受地质环境和施工条件影响较大,导致其应用范围不大.本文依托吕梁城市地下综合管廊工程对支护冠梁施工应用土模的可行性进行一系列试验,通过对现场不同压实度的土体中成型的现浇试件、同条件预制立方体试件以及标养立方体试件的28 d强度对比,发现混凝土的强度随着土体压实度的增大而提高,当压实度达到一定程度时,混凝土强度受压实度的影响变得极小;在低压实度条件下,混凝土水化、硬化前期受土体作用影响最大,其影响效果随着压实度的提高而逐渐降低.As a traditional formwork construction technology,“soil formwork”not only reduces the investment of concrete formwork and saves economic costs,but also cuts down the turnover period of concrete formwork and speeds up the construction progress.However,soil formwork is greatly affected by geological environment and construction conditions,resulting in a small application range.Based on the underground comprehensive pipe gallery project of Lvliang City,a series of tests were carried out on the feasibility of applying soil formwork to the construction of supporting crown beam.By comparing the 28-day strength of cast-in-situ specimens,precast cubic specimens under the same conditions and cubic specimens maintained by standard,it was found that under the condition of low compactness,the strength of concrete followed that of soil.When the degree of compaction reached a certain degree,the strength of concrete almost kept unchanged,and the strength of cubic specimens under the same conditions was almost the same as that of standard specimens after conversion.Under the condition of low compactness,the effect of soil on the early stage of hydration and hardening of concrete was the greatest,and its effect decreased gradually with the increase of the degree of compaction.

关 键 词：土模 混凝土强度 压实度 影响 试验 

分 类 号：TU990.3[建筑科学—市政工程]