（1 西安建筑科技大学土木工程学院， 西安 710055； 2 中国建筑科学研究院有限公司， 北京 100013）

［摘要］混凝土碳化系数是一般大气环境下混凝土结构耐久性的重要指标，为研究实验室加速碳化和工程结构自然碳化的相关性，在北京地区暴露26年的混凝土长观试件的多次实测碳化深度基础上，从长观试件中钻取未碳化的混凝土制作成圆柱体试件，在实验室进行加速碳化试验，分析实验室加速碳化和室外自然碳化的规律，并研究两者实测碳化系数的相关性。结果表明，混凝土抗压强度值从29-8MPa增长到57-2MPa，增幅接近一倍，加速碳化28d的碳化深度和50年自然碳化深度基本接近，从混凝土抗碳化能力随强度增长而提高的角度考虑，采用龄期28d混凝土试块的加速碳化试验结果作为混凝土耐久性设计或者评估的依据是偏于保守的做法。

［关键词］混凝土碳化； 长观试件； 自然环境； 加速试验； 相关性

中图分类号：TU528文献标识码：A文章编号：1002-848X(2019)09-0111-04

Experimental study on correlation between natural carbonation and accelerated carbonation of long-term observation concrete specimens

Sun Bin1,2, Mao Shiyang2, Wang Jingxian2, Di Xiaotan2, Ren Ronghong2

（1 School of Civil Engineering, Xi′an University of Architecture and Technology, Xi′an 710055, China;2 China Academy of Building Research, Beijing 100013, China)

Abstract:The carbonation coefficient of concrete is an important indicator of the durability of concrete structures in general atmospheric environment. In order to study the correlation between the accelerated carbonization in laboratory and the natural carbonization of engineering structures, the uncarbonized concrete was drilled from the long-term observation specimen to make a cylindrical experimental piece, based on the multiple measured carbonization depths of concrete long-term observation specimens exposed in Beijing for 26 years. Accelerated carbonization experiment was carried out in the laboratory to analyze the laws of accelerated carbonization in the laboratory  and outdoor natural carbonization, and to study the correlation between the measured carbonization coefficients under the two conditions. The results show that the compressive strength of concrete increases from 29-8MPa to 57-2MPa, and the increase is nearly doubled. The carbonization depth of accelerated carbonization for 28d is almost the same as the natural carbonization depth of 50 years. From the perspective of  the carbonation resistance of concrete increasing with the increase of strength, it is a conservative measure to adopt accelerated carbonization experimental results of the 28d concrete specimen as the basis for the design or evaluation of concrete durability.

Keywords:concrete carbonation; long-term observation specimen; natural environment; accelerated experiment; correlation