Geopolymer technology has allowed the development of eco-friendly construction materials with high mechanical properties using industrial wastes and residues. However, geopolymers show fragility and low ductility behavior similar to Portland cement-based materials. This article focuses on the evaluation of jute and sisal fibers as reinforcement of a geopolymer matrix produced from residues of Fired Clay Brick Powder (FCBP). Control samples with no fibers and reinforced matrices with different contents of jute (ranging from 0.5 to 2.0 wt%) and sisal fibers (ranging from 0.5 to 3.0 wt%) were produced to study the effect of the fiber type and content on the mechanical properties of the resulting geopolymer composites. Mechanical characterization consisted of compression, splitting tensile, and three-point bending tests. The results of compression and splitting tensile tests showed the exist...

The development of alkaline activated materials has enabled the production of eco-friendly alternatives for the construction industry. In the present article, the mechanical characterization of a new structural masonry system composed of fiber-reinforced lightweight pozzolana-based blocks and cement-lime mortar was performed. The mechanical characterization involved uniaxial compression tests in prisms and diagonal compression in wallets. The results indicate that the compressive and shear strength of the masonry system is up to 3.24 MPa and 0.38, respectively. The results obtained indicate that the evaluated system is structurally efficient and that can be used as both non-load and load-bearing walls. © 2020 Trans Tech Publications Ltd, Switzerland.

Lightweight geopolymers are alternative low-carbon footprint building materials with high potential to produce value added products for the construction industry such as low-density masonry units. This work focuses on presenting the development of a new lightweight masonry block using natural pozzolana-based geopolymer mortar, hydrogen peroxide as a foaming agent and jute fibers as reinforcement additive. The experimental plan allowed the optimization of the production process and the definition of the optimum quantities of hydrogen peroxide content, pozzolana: fine aggregate ratios and the appropriate amount of fibers to be incorporated. The experimental results demonstrate the feasibility of the production of new masonry units, which can achieve up to 8.1 MPa of compressive strength after 28 days of fabrication with reduced bulk densities of 1269 kg/m3.

The improvement of the mechanical properties of geopolymer matrices relies on the characteristics of the source materials as well as in proper optimization of the alkaline activating solution and curing conditions during geopolimerization. This study presents the optimization analyses carried out to determine the proper production conditions of Fired Clay Brick (FCB) and Natural Pozzolana (NP)-based geopolymers. The results indicate that high compressive strengths of up to 37 MPa and 26 MPa can be obtained for FCB and NP-based geopolymers, respectively when the proper production conditions are employed. The optimum alkaline solution for FCB consisted of Ms = 0.60, Na2O content of 8%, water/binder ratio = 0.27 with oven curing conditions between 65 and 80 °C for 7 days. On the other hand, NP-based geopolymers with the highest mechanical properties were obtained with an alkaline solution ...