Experimental Study of Thermophysical and Mechanical Properties of Refractory Clay Tilled into Straw-fiber Stabilized Blocks

In this experimental study, we have determined both thermo-physical and mechanical properties of raw soil blocks stabilized with fiber straws. Also was studied, the influence of straw content incorporated in the blocks for both properties. Thermophysical properties are determined using a device we designed and produced in the Technical Block of the University of Antananarivo between November 2014 and September 2015. This device uses a hot plane. Mechanical properties are determined using a mechanical press.

The results of our study show that the stabilization of raw mud blocks with straws enables to improve both its thermal and mechanical properties. Indeed, stabilization has enabled to decrease thermal conductivity by 44.92%, diffusivity and thermal effusivity by 30.77% and 33.81% respectively relative to the blocks without stabilizer. But it increases the heat capacity of 6.81% compared to blocks without stabilizer.

The compressive strength has been increased by 58.96% and drying shrinkage has been decreased by 22.25%. The resistance to the maximum deflection is 0.477 MPa for 4.81% of straw rate.

Stabilizing the clay with a straw has improved these thermophysical and mechanical properties respectively in insulation and increased strength, showing that it can be used bearing material in the construction of bioclimatic habitats.