混凝土环形收缩试验的研究进展  

Ring Shrinkage Test of Concrete:a Review

作　　者：张超[1] 方胜 黄伟 赖志超 陈添平 ZHANG Chao;FANG Sheng;HUANG Wei;LAI Zhichao;CHEN Tianping(College of Civil Engineering,Fuzhou University,Fuzhou 350108,China;Lets Holding Group Co.,Ltd.,Xiamen 361004,Fujian,China;Fujian Fuping Railway Co.,Ltd.,Fuzhou 350000,China)

机构地区：[1]福州大学土木工程学院,福州350108 [2]垒知控股集团股份有限公司,福建厦门361004 [3]福建福平铁路有限责任公司,福州350000

出　　处：《材料导报》2023年第4期116-125,共10页Materials Reports

基　　金：国家自然科学基金(E51508102);福建省自然科学基金(2019J01233);中国博士后科学基金(2020M671951);福州大学贵重仪器设备开放测试基金(2020T035);高性能土木工程材料国家重点实验室开放基金(2019CEM003);江苏省土木工程材料重点实验室开放基金(CM2018-04);长江科学院开放基金(CKWV2019750/KY)。

摘　　要：实际工程中,由于混凝土自身和外界作用,体积会发生变化,材料产生收缩。自从混凝土的收缩性能研究进入人们的视野以来,就不断有新的研究方法被提出。根据约束作用,混凝土收缩一般分为自由收缩和约束收缩。其中,环形约束收缩试验因其装置简单、易操作、应力大小均匀、易于推广及标准化、体现约束条件下收缩和应力松弛的综合作用等优点,被广泛应用于收缩试验,能有效评价混凝土的抗开裂性能。然而,环形约束收缩试验有着开裂位置随机、对高抗裂性材料约束不足、开裂时间较长或不开裂等问题。对此,许多学者针对诱导裂缝位置与加大开裂敏感度的方面提出使用不同的改进装置。另外,试验的影响因素与开裂指标也是关系到环形约束收缩试验方法科学实用与否的重要因素。在方法改进方面,国内外学者提出了内置尖角法、内外环偏心法、椭圆环法等新的实用方法;在试验影响因素方面,众多学者认为约束度、湿度、纤维等举足轻重;在开裂指标方面,现阶段主要有基于抗拉强度、断裂力学、开裂系数、应力率系数等实用的开裂指标可供参考。本文从试验装置、影响因素、开裂指标等方面总结了混凝土环形约束收缩试验的研究进展,分析了混凝土环形约束收缩试验的影响因素,以期为此类试验方法的改进与应用提供参考。In the current engineering practice,the volume of concrete is usually changed causing the formation of shrinkage due to the internal and external actions.Since recent research focusing on the shrinkage properties of concrete emerged,new research methods have continuously been proposed.The shrinkage of concrete is generally divided into free and confined shrinkage according to the limitation actions.One of the recent adopted testing methods is the ring confined shrinkage test that is widely used in testing the shrinkage of concrete.The wide usage of this method is due to its advantages that include the simple devices,easy operation,uniform stress,and easy popularization and standardization.It can also reflect the comprehensive effects of shrinkage and stress relaxation under constraint conditions.Therefore,it has the ability to effectively examine the cracking resistance of concrete.However,this testing method has some drawbacks such as the random cracking position,insufficient restraint on materials with high cracking,and long cracking time or no cracking.Thus,many scholars have suggested different improved devices that can induce cracks position and increase the cracking sensitivity.Besides,the influencing factors and cracking indicators of this testing method are also important for the scientific and practical application.For methods improvement,many studies conducted recently either locally or abroad have proposed new practical methods such as built-in sharp angle,inner and outer rings eccentricity,and elliptical rings.Several factors such as the constraint degree,humidity,fiber,etc.,have an important influence on this testing method,while there are some practical cracking indexes based on tensile strength,fracturing mechanics,cracking coefficient,stress rate coefficient,etc.,for the cracking indicators.This review summarizes the available research on the progress of concrete ring confined shrinkage test,from a detailed and comprehensive perspective of the experimental devices,influential factors and cracking

关 键 词：环形约束收缩试验 试验装置 约束度 湿度 开裂指标 

分 类 号：TU528[建筑科学—建筑技术科学]