Research On Mechanical Properties Of A New Type Of Fired Shale Self-Insulation Block Masonry

China holds a great amount of energy consumption in the world, where the building energy consumption occupies nearly one third of the whole society's consumption. Because of such significant share, it will be definitely meaningful to conduct studies on both building energy efficiency and green building materials. Fired shale-farinosecoal porpous wall material is one of the advantageous green building materials, performing well in energy efficiency and material saving. To the best of the authors' knowledge, most previous researches were focused on the hollow vertical-walls. However, the traditional structural properties of the walls have some disadvantages, such as leakage of the mortar, limited usage of the structure strength, which would tend to cause mortar wastes and affect the energy efficiency of the building. To that end, fired shale-farinosecoal porpous blocks with 9 rows of horizontal hollows and the effects of self thermal insulation, namely novel fired shale-farinosecoal block with self thermal insulation, are proposed in the current study. Furthermore, the computational theory and design methods contained in the present masonry code could not be applied to the newly presented walls directly, in that there exists significant difference between the novel fired shale-farinosecoal block masonry with self thermal insulation and traditional walls in structure properties. Additionally, the basic mechanical characteristics of the masonry blocks and thermal performance of the masonry walls are evaluated as follows:To evaluate the deformation characteristics and failure mechanism of this new form of blocks, axial-load capacity tests have been conducted on 2 groups(12 items) of specimens, from which the formula for calculating average compression strength of the blocks are proposed. According to the stress-strain curves, the logarithmic stress-strain formula expressions of the novel fired shale-farinosecoal block masonry with self thermal insulation are concluded. Meanwhile, the calculation of elastic modulus of this novel form of blocks is also presented in this paper.Using ANSYS software, a full-scale finite element model(FEM) of the specimen has been built and analyzed. The axial compression performance of the blocks, by determining several parameters in the FEM analysis and appropriate assumptions, are simulated and the cracking, stress distribution and the compression strength of the blocks are obtained respectively. The result is shown to be well correlated with the tests results. Thus, the finite-element modeling is able to be used for simulating the structure behaviors of this new fired shale-farinosecoal block masonry with self thermal insulation under compressive loads. By further analysis, the strength of the masonry increases by the increase of the cross rib width of the block, but decreases by the increase of the hole row number of the block.Based on the experimentally studies on shear capacity along bed joints, both the failure properties and mechanism of the new fired shale-farinosecoal block masonry with self thermal insulation are analyzed. It is observed that the shear strength of the new fired hollow horizontal-block masonry is 1.6 times the strength of fired perforated brick masonry, demonstrated in the design codes. In addition, the mortar, between the upper and lower groove, is noted to be cracked by shear force, and, through calculation, the mortar should not be ignored in bearing shear forces at the groove. Consequently, the calculation expression of average shear strength of this form of blocks is developed in this paper.The thermal calculation model of this novel block walls is proposed in the study, including the theoretical calculation of both heat transfer coefficient and thermal inertia index. Besides, the experimental studies on heat transfer coefficient are also performed. The results show that comparing with the current energy efficiency standards in Hunan Province, the newly presented walls reach the required level, i.e., 50% energy savings. Given its thermal performance, internal and external wall insulation treatment could not be necessary for this novel wall structure.In summary, the basic mechanical properties and thermal performance of the novel fired shale-farinosecoal block masonry with self thermal insulation are obtained, which might serve as theoretical basis for the following research and the revision of other correlated design codes.