Experimental Research On Basic Mechanical Properties Of Compound Self-insulation Concrete Block Masonry In Northeast Cold Region

There are strict requirements of mechanical properties and thermal performance of building envelope for northeast cold region. According to survey, the 490mm thick solid clay brick is commonly used as wall in the northeast cold region, which heat transfer coefficient is 1.25W/(m2·K). This paper intends to develop self thermal insulation block with good energy saving effect, light weight, wall thickness, and high strength.Based on the existing research results on the subject, the mix ratio adjustment of concrete hollow blockis is put forward combined with the conclusion about orthogonal experiment of vibration pressure ceramsite concrete molding compressive strength When add the rock wool and slag, the bearing block is obtained which thickness is only 280mm, heat transfer coefficient are 0.31W/(m2·K) and 0.39W/(m2·K) and strength grade are MU3.5 and MU5.0. The new block can not only meet the requirements of section of the building, but also extremely reduce the thickness of wall, save material and increase the use area.The influence of vibration compression molding process and lightweight aggregate components as haydite to the strength development of new composite self-insulation concrete blocks was explored by block mechanical testing, and fit the relationship between blocks compressive strength and age by combination previous studies and Matlab software. Then the paper measured heat transfer coefficient of new blocks through hot box thermal performance detection of three block walls. After explored the impact of moisture content on the block wall ceramic thermal performance, the paper gave the recommendations of the wall thermal performance testing combined with the characteristics of hot box method.Based on four groups the new compound self-insulation concrete block masonry axial compression tests, the paper concluded the compression failure characteristics and compression performance (crack factor and strength utilization factor).The preliminary inquiry of matching problem about new block and mortar lead to the proposal that "block strength level should be higher than the strength grade of mortar" in masonry standard is not suitable for the new type composite thermal insulation concrete block. The suggestions for hollow block that mortar adaptation strength should be higher than the compressive strength of block, but slightly lower than the concrete strength of the parent metal is obtained through theoretical analysis. After the analysis of test results, the paper found that the new type of block masonry compressive strength values were higher than the two row hole or multi hole light aggregate concrete block masonry strength of MU5.0+Mb5.0, and proved that it can be used as load bearing wall of two story masonry structure in the northeast cold Village. Experimental results showed that the compressive strength formula of specification provides is applicable to the new block masonry, meanwhile, the paper gave proposed formula of compression stress-strain curve, proposed elastic model and poisson’s ratio.Based on four groups of new compound self-insulation concrete block masonry shearing tests which along the mortar joints, the paper concluded that the shear strength of new block masonry which along he mortar joints is higher than the shear strength of common block masonry. Because the void of block inserted EPS thermal insulation board, which made the realization of laying mortar to blind hole block, and it can effectively avoid mortar leakage.