Experimental Study On Uniaxial Compressive Property And Stress-stain Relationship Of Hollow Concrete190Block Masonry

The history of the application and development of concrete block masonry hasbeen more than100years in foreign countries, in China it has been more than threedecades. With gradual elimination of clay brick masonry，block masonry structure willhave broad and great prospects.Studies have found that the parallelism between the bearing surfaces of block canstrongly impact strength of blocks. With the maximum improvement of parallelism, themeasured value of block strength is1.67times of the values obtained by standard means,and the coefficient of variation has decreased by52%, this means that the reliabilityimproved obviously. Inspired, it is necessary to study whether and how the parallelismwill impact the basic mechanical properties of block masonry. The current codes inChina use cement mortar and the level of foot to do capping work, it can only ensure theflatness of the surfaces but not the parallelism, the standard is lack of assurancemeasures and related provision. The standard of parallelism between bearing surfaces isof great importance for the basic mechanical properties research work and developmentof block masonry industry.In order to study this issue, this article has designed a special instrument. Using theinstrument and high-strength gypsum, we can increase the parallelism and make it to thebest.There are a total of25hollow block specimen in the experiment of this paper,20ofthem are capped by the instrument and high-strength gypsum, the left are capped by thecement mortar and the level of foot. By the uniaxial compressive test of the specimen,we get data of the ultimate strength, elastic modulus, Poisson’s ratio and so on,furthermore, the entire curves of load verses displacement were well recorded.According to the analysis, a standard procedure and test method was established. Theresults showed that the parallelism between the bearing surfaces has a significant effecton mechanical properties of block masonry, quantitative relations between them need tobe further studied.In addition, according to the load verses displacement curves of specimens, andlearn from the stesss-stain relationship of concrete proposed by Guo Zhenhai, thestress-strain relationship of190hollow block masonry were obtained.