Physical And Mechanical Properties Of Light Aggregate Concrete And Numerical Simulation To Thermal Transmission Of Mansonary Block

In the era of non-renewable energy, demand of energy conservation increases rapidly. As a kind of building material with lightweight and heat preservation, insulation masonry blocks become popular products as well as research targets. To analyze the effect of void type on thermal transmission of masonry bloc k, research on light aggregate concrete and mortar used in masonry block is carried out in this paper, followed by numerical simulation to thermal transmission of masonry block. Leca, shale ceramsite, cinder and other aggregates are used in this paper to d esign mix proportion and make light aggregate concrete for different strength. To some extent, the design process of mix proportion is made easier by adopting an empirical formula. All the concrete made meet the expected requirement on strength. Concrete made by shale ceramsite reaches a higher strength than concrete made by leca, while remaining similar volume weight. The thermal conductivity coefficient of concrete made with two type of ceramsites are quite close, while concrete made with cinder has a higher volume weight than former two as well as thermal conductivity coeffic ient. C oncrete made with fly- ash ceramsite attain the highest volume weight among these concrete, also as its strength and thermal conductivity coefficient.To make masonry mortar with heat- insulated property, clay sand and fine cinder are used to partly replace with sand. Properties of these two kind of mortars doesn’t change much when such ingredients are mixed at low proportion. As proportion of such ingredients reach a relative ly high level, the thermal conductivity coefficient dropped by 53% and 34%, respectively. Comparison shows suitable particle size with enough proportion of such ingredients may obtain relatively low thermal conductivity coefficient.According to the data, heat transmission coefficient to one type of masonry wall is calculated. Then, the heat transmission coefficient of same masonry wall build by same masonry block is test by using hot box method. The results of real test is compared with the calculated result, which shows the latter is only 11.5% higher than the test result. The difference suggests that c alculating heat transmission coefficient is practicable and this method can be used to estimate a relatively exact heat transmission coefficient.At last, 3D model of masonry blocks are created by using ANSYS Work Bench, and thermal transmission of models are analyzed. The distance between two longitud inal ribs in two contiguous line further than 40 mm may bring enough heatresistance. Results suggest that, symmetrical void pattern benefit more to the heat resistance of masonry block than unsymmetrical void pattern. Increasing number of rows can increase the complexity of internal shape, and raise the heat resistance relatively effectively.