Experimental Study On The Properties Of The Autoclaved Fly Ash Brick Masonry With Axial Compression

Wall reform policy towards energy save and soil save is put forward by the country as the implementation of sustainable development in china continuing. Therefore, masonry structure committee of china engineering construction standard association draws up the Technical Code for Masonry Structure of Autoclaved Fly Ash Brick to popularize the utility of autoclaved fly ash brick. To accomplish the study work assigned by the country on axial compressive behavior of autoclaved fly ash brick and solid brick, By means of software ANSYS, a finite element program, the influence towards internal force of perforated brick caused by the appearance and ratio of the hole was analyzed. and provide a scientific and practical valid of design, the following research are carried out.In order to find out the behavior of compressed autoclave coal ash brick masonry, 12- groups (36in all) short columns under axial compression were studded. The 36 short columns were bricked using 4 different levels of mortar, 2 different levels of mortar joint, and 2 kinds of bricks (autoclave coal ash brick and solid brick). During this experiment the strength of mortar affected by different kinds of bottom-formworks also be measured and analyzed. Still in this experiment rigid elements are introduced for a better understand of the full process and deformation performance of the autoclaved fly ash brick under axial compressive load.It was found that:①The process and characters of compressive failure of autoclaved fly ash-lime brick masonry under compression is similar to that of fired brick masonry.②the bond between ordinary mixed mortar and solid brick with smooth surface is comparative poor, therefore the strength of mortar may have little contribution to the compressive strength of masonry, especially for middle and high strength mortar. However the special mortar can raise the compressive strength of masonry remarkably.③the average compressive strength computing formula of autoclaved fly ash perforated brick masonry structure in current regulation is feasible and conservative enough.④The value of elasticity modulus of the autoclaved fly ash brick masonry was higher than the value in regulation , and the poisson ratio can be taken as 0.15.⑤The descending branch of stress-strain full curves was obtained through the special equipment designed by the author.⑥The compression constitutive relationship can be expressed in a 3 segments' stress-strain curves, and the ascending branch includes the straight Segment and the curve segment while the descending section is only consist of a curve segment. Compared with the conventional constitutive relationship under compression, this curve is more close to measured data.⑦The appearance and ratio of the hole are the main factors affecting the strength and other mechanical properties of this brick.