Innovative Materials for Sustainable Construction

Abstract

The construction industry has focused on trying to minimize and control the environmental impacts caused within the process of production and manufacture of fired bricks, for this reason the present research proposes five different alternative mixtures for the elaboration of ecological bricks, four of these based on soil-cement and one obtained through a geopolymerization process, using raw materials from the amazon region and the southern highlands of Ecuador, such as soil from the Centza mine (MC), sand from the Quiringue mine (MQ), organic correctors of husk rice (RH ), peanut shell (PS), natural gypsum (G) from the Malacatos sector and fired brick residues from the same sector. The raw materials were characterized (analysis: physicochemical and mineralogical); the soil-cement-based combinations used different percentages of substitution of organic correctors and gypsum, the optimum percentage of water and cement was determined through the compaction test and resistance to simple compression respectively, the samples were cured and tested at ages of 7, 14 and 28 days. In the geopolymerization process, an alkaline solution NaOH was used in different concentrations of molarity and solution contents, the specimens were cured at temperatures of 90 °C, 120 °C, 150 °C, 180 °C and 200 °C. The different combinations were subjected to indirect traction with the purpose to determine the optimal mixture and subsequent estimation of the compressive strength of bricks applying the Griffith criterion, the results were validated by the finite element method, obtaining strengths of 4 MPa in the combination soil-cement sand (SC_Ar1), in soil-cement rice husk (SC_RH2) and soil-cement peanut shell (SC_PS2) mixtures its resistance is 3 MPa, while in the soil-cement gypsum (SC_G4) mixture the resistance is 6.90 MPa and finally the resistance in geopolymeric mixture (GBW) is 13.75 MPa; In this way, the optimal combinations comply and increase the resistance to simple compression of bricks by 35% the SC_Ar1 mixture, 130% in the SC_G mixture with respect to the spanish standard and 129% the GBW mixture with respect to the ecuadorian standard.