The Experimental Study On The Autoclaved Lime-sand Brick Masonry To Improve The Mechanical Properties Quality

As environment protection and energy saving has increasingly become a hot issue in today’s housing industry, and with the in-depth development of wall materials innovation, the autoclaved sand-lime brick has emerged as a new material. It is gradually applied in rural areas and small cities for the advantages of convenience, cheap, low energy consumption, good effect on insulation and high compressive strength. However, the autoclaved sand-lime brick is not in widely use because of its smooth surface and the feature of water dehydration lag,which will lead to a low shear strength and a poor bonding capacity with mortar.It is discovered that the shear strength of autoclaved sand-lime brick is only 70 percent of common clay brick.A lot of researches have been done both at home and abroad to improve the shear resistance of autoclaved sand-lime bricks.Based on these researches, the material performance and the basic mechanical properties of both autoclaved sand-lime bricks with transverse grooves on surface and bricks with oblique grooves have been found in our experimental studies.In addition, the largest slotted form on improving shear strength of autoclaved sand-lime brick masonry has also been concluded. Moreover, the experiments provided a comparative analysis of the basic mechanics performances of autoclaved sand-lime brick and autoclaved fly ash admixture of sand-lime brick. The main contents are as follows:(1) Through the experimental study on the mechanical properties of autoclaved lime-sand brick masonry,of which has transverse grooves and oblique grooves in the shape of rectangular width 20mm, depth 1.5mm respectively,the best way of notching manner have been found. The shear performance of autoclaved sand-lime brick wall can be improved in the largest extent and it will cause the minimal impact on the brick’s compression performance.(2) On the basis of experimental studies and theoretical analysis, this paper concludes the average value and design value of shear strength of autoclaved sand-lime brick wall with transverse grooves on surface and oblique grooves on surface, which can provide reference for the masonry norm of those kinds of autoclaved sand-lime brick wall.(3) The experiments made researches on the flexural strength and compressive strength of common sand-lime bricks, autoclaved lime sand brick with transverse grooves or belt chute on the surface, perforated sand-lime brick and autoclaved lime sand brick blended with fly ash. A comparative analysis of the impact on the material properties have been made among the autoclaved lime sand brick with grooves, the perforated sand-lime brick and the autoclaved lime sand brick blended with fly ash.(4) Comparison and analysis have been made on the deformation performance, failure characteristics and elastic modulus of autoclaved sand-lime brick, autoclaved sand-lime brick with chute, perforated sand-lime brick and autoclaved lime sand brick blended with fly ash after press.