Composition for a pumice concrete that produces a rapid set.

Abstract

This application is for a lightweight concrete mix that produces rapid setting for use in construction, comprising the following components: a) calcined powdered pumice corresponding to a sieve size below 0.63 mm, b) pumice stone or vesicular volcanic glass with a particle size of 5 to 20 mm containing silica and alumina, c) pumice or volcanic glass sand in different particle sizes corresponding to a sieve size of 1.25 to 5 mm containing silica and alumina, d) crushed rock sand corresponding to a sieve size of 1.25 mm to 2.5 mm having irregular edges and, as processed, free of impurities, e) recycled bristle or crystalline polymer PET1 with filaments 0.80 cm to 1.40 cm long and 0.40 mm thick, f) SIKA AER air-entraining admixture, g) cement, and h) water. In addition,This application mentions a process for obtaining this lightweight concrete mix comprising the following stages: a) the pulverized pumice is obtained through a crushing process where it is dried and then calcined at a temperature of 800 °C to 1,000 °C, calcining the impurities into silica and magnesium hydrates, b) due to its crystalline structure, the hydraulic properties are concentrated through slow crystallization when the calcined pulverized pumice reaches ambient temperature and is exposed to water, where an exothermic chemical reaction occurs that releases heat and forms calcium hydroxide, c) when the thermally calcined crushed pumice is mixed with cement, it fixes the lime contained in the cement, concentrating the adhesive properties and preventing a reduction in the cement's binding effectiveness in the mix due to the high percentage of fine aggregates in this composition.d) The lightweight concrete mix undergoes a double process of sealed, millimeter-sized air chambers: first, by saturating the gravel with water to over 50%, and second, by adding an air-entraining admixture to the mix in the aqueous stage, expanding the fine aggregate with micro-bubbles; and e) Recycled bristles obtained from the recycling of high-strength PET1 plastic bottles are incorporated into the mix through a melting process at temperatures exceeding 200 °C. These bristles are then subjected to an extraction method using a commercially available extruder, distributing them three-dimensionally throughout the mix. Furthermore, this application indicates the use of the lightweight concrete mix for manufacturing: a) reinforced concrete thermal walls, b) reinforced concrete thermal slabs, c) reinforced concrete beams and ties, d) reinforced concrete pillars and columns, e) reinforced concrete structural thermal panels, and f) thermal concrete slabs or floors.