Study On Effects Of Immersion Time On The Compressive Strength Of Mortar And Brick Specimens

Immersion in water will increase the moisture content of building materials,which will affect its properties such as compressive strength,elastic modulus and so on.At present,the properties of concrete with different moisture content has been studied,and there is also some works on immersed masonry materials,but the compressive strength of mortar and brick specimens with different immersion time has not been studied.Based on the analysis of the mechanism of contraction and intensity caused by the loss of water in masonry,the paper presents the micro-mechanism of changes in compressive strength with the increase of moisture content.Meanwhile,the compressive strength of specimens of mortar and brick with different immersion time, different grades of strength were tested.It is found that when the immersion time increases,the compressive strength of mortar and brick specimens decreases.In add, drying method are used for the determination of moisture content,obtaining the changes of compressive strength with different moisture content.According to the effect of the mechanism about the change of the compressive strength of mortar caused by different moisture content,the test results are analyzed. There are two main reasons that lead to the compressive strength of mortar and brick specimens reduces:the lubrication of water between mortar aggregates and the gel breaking pressure caused by absorbed water.Finally,based on the experimental results, formula of mortar compressive strength considering moisture content are presented.