Evaluation of the Use of Cellulose, Latex and Metakaolin in the Production of Cement Composites with Low Water Absorption and High Modulus of Elasticity

In this work, the aim was to study the influence of cellulose Kraft pulps, natural rubber latex, and metakaolin in the optimization of the values of flexural strength and water absorption of cementitious composites through the design of experiments (central composite design) at 28 days of age. According to the design of experiments, the composite with 1.252% cellulose, 1.126% latex and 37.06% metakaolin presented the optimized value of the modulus of elasticity (21.89 GPa). In addition, an increase in the values of modulus of elasticity for composites with lower cellulose contents was observed. Latex and metakaolin provided small variations in the modulus of elasticity. For water absorption, only cellulose exhibited significant interference. Thus, lower values of water absorption were found for lower concentrations of cellulose. The optimized composite that showed less water absorption was with 1.5% cellulose, 0.02% latex, and 4% metakaolin, with 10.28% absorption. In view of the results obtained, it was concluded that the use of central composite design, the molding method adopted, and the limits of constituents used allowed the optimization the values studied responses (modulus of elasticity, and absorption).