MECHANICAL ANALYSIS OF A SUSTAINABLE BUILDING PREFABRICATED ELEMENT BASED ON A STABILIZED RESIDUAL QUARRY SLUDGE

A masonry prefabricated element will be produced from the process of reusing a sludge generated by the Colombian mining industry, especially the sandstone quarries, that become pollution agents ending up in the hydric sources, impacting negatively the environment. This waste was previously stabilized with the addition of Ca(OH) and Na(OH), the optimal mixing specifications were obtained using a response surface model accomplishing low quantities of stabilizers and the use of the waste as the main component, achieving improvements in load-bearing capacity (8 MPa) and the durability according to its dimensional stability, upgrading the traditional techniques. In this work, computational simulations are performed to understand some mechanical responses in stabilized-sludge masonry elements with different geometries and to compare the simulation results with common materials in the literature. Simulation outcomes showed that hollow-block geometry saves up a considerable amount of material and improves stress distribution compared with a solid block. Also, the mechanical simulation of the stabilized-sludge elastic zone achieved a better performance than a compressed earth block, which is a similar material used in construction. This way, the design of more sustainable elements through an innovative methodology based on statistics, mathematical and computational models, saving materials, time, and energy is sought, generating an economic and environmental impact.

Shear properties of a new type recycled aggregate concrete interlocking hollow block masonry with axial load

Comprehensively considering the positive contribution of energy conservation and the reduction of the construction skill requirement for workers, a new type of interlocking hollow block using recycled aggregates concrete (IHAC) with the compressive strength defined as MU10 was proposed, which could help improve more than 56% of the construction efficiency compared to common used concrete hollow blocks. In order to study the shear properties and promote its application in building engineering, the shear strength of 10 groups (three specimens for each group) of masonries considering different axial stress level and whether or not to use concrete in the grouting holes were studied, and the failure mode as well as the shear strength of the masonries were analyzed. And then, the calculation formulas for predicting the shear strength of the IHAC masonry were obtained by using the parameter fitting method based on the Coulomb failure theory, which could well reflect the parabolic shaped changing characteristic of the shear strength with the increasing of the axial stress, and the maximum difference was within 18% between the calculated and test results.

Mechanical Properties of a New Type Recycled Aggregate Concrete Interlocking Hollow Block Masonry

Considering the advantages of energy conservation and reducing the construction skill requirement of the workers, a new type of interlocking hollow block using recycled aggregates concrete (IHB-RAC) with the compressive strength up to 10 Mpa was proposed, which could help improve more than 56% of the construction efficiency compared to commonly used concrete hollow blocks. In order to study the mechanical properties and promote the application of this new type block in building engineering, the masonries considering different strengths of mortar and the concrete used in the grouting holes were designed, and the corresponding compressive and shear strength, as well as the failure mode of the masonries were studied according to the test results. Then, experimental results were compared with the calculated values obtained from Chinese code GB50003-2011 to check the suitability of the standards. In order to make an accurate prediction of the compressive strength of the masonry, modifying coefficients were suggested considering the positive contributions of the connecting keys. In addition, according to the test results, an appropriate calculation method for accurately predicting the shear strength of the grouted IHB-RAC masonry was proposed by separately considering the effort of the mortar and the grouting hole concrete.

Seismic Performance of Masonry Walls Built with New Type of Fired Shale Hollow Blocks

This paper presents the cyclic loading test results of a new type of fired shale hollow block masonry walls. Six specimens were designed including two specimens without reinforcements (bare walls) and four specimens constrained by structural columns (reinforced walls). The influences of aspect ratio, vertical compressive stress, and structural column on the seismic performance of the specimens were investigated. The failure mode, bearing capacity, ductility, stiffness degradation, and energy dissipation of specimens were analyzed. The results showed that the crack patterns of specimens changed from the horizontal straight shape (bare walls) to “X” shape (reinforced walls), and the corresponding bearing capacity, ductility, stiffness degradation, and energy dissipation of the specimens were improved. With the increase of the vertical compressive stress, the ductility and the secant stiffness of the specimens increased. Moreover, with the decrease of aspect ratio, the bearing capacity and secant stiffness of the masonry walls increased, while the energy dissipation capacity decreased. This paper confirms that fired shale hollow block walls could meet the seismic requirements through appropriate design, which could promote the application of this new type of block in civil engineering.