José Manuel Vicente Gómez Soberón

Effect of curing temperature in the alkali-activated blast-furnace slag paste and their structural influence of porosity

Due to the environmental problem posed by the use of Portland cement as construction material, it becomes necessary the search for supplementary cementitious materials that mitigate the ecological damage caused by it. Because the chemical similarity and the high cementitious powers of the blast furnace slag, it is used in the generation of geopolymers in a cement total replacement. This research focused on the study of the influence of the curing conditions on the final properties of blast furnace slag establishing three variables: no cured process (N-C), cured of controlled temperature of 45°C (CT45-C) and room temperature cure (RT-C); evaluating the mechanical behavior until 28 days of age and the water porosity index. The results show that geopolymers based on blast furnace slag has a behavior similar to hydration maturity of Portland cement and curing process decreases the porosity; On the other hand, applying a controlled temperature generates densest resistant pastes such as the variable CT45-C which reach the highest value of resistance in all curing ages.

Chloride corrosion of embedded reinforced steel on concrete elaborated from recycled coarse aggregates and supplementary cement materials

As a result of contributive and sustainable strategies on concrete industry, researches are presently being developed, which are focused on improving durability of reinforced concrete structures as well as partially or completely replacing their components by recycled materials. In the case of steel bars, corrosion is considered as the major durability menace to reinforced concrete. The present research employed coarse aggregate from recycled concrete and supplementary cement materials, which are byproducts of industrial processes, such as fly ashes and silica fume, for the elaboration of sustainable concretes and for the evaluation of their behavior faced to chlorides exposure. Compressive resistance, electric resistivity, loading transfer resistance and ion chloride permeability resistance are the parameters which were determined from the resulting test specimens, thus specifying the minimum required properties for concrete, in accordance with regulations that guarantee its durability faced to chloride actions. From results obtained it is concluded that concrete elaborated using a 100% of recycled coarse aggregate and supplementary cement materials improves its behavior as far as resistance and durability are concerned, in comparison to conventional concrete.

New concrete additive by chemical recycling on PET

Due to the problem that represents the accelerated production of waste from the consumption of polyethylene terephthalate (PET), it becomes necessary to look for alternative solutions; chemical recycling is a suitable method for conversion into a material with potential application in concrete additive, such as unsaturated polyester resins; with the above improvements and conservation of non-renewable raw materials can reduce the environmental impact. This investigation was focused on obtaining the synthesis of a polymeric resin by the method of glycolysis, and their characterization by Infrared Spectroscopy (FT-IR); the results show that the recycled materials (PET and its processing) are similar to reagents made from primary materials so that it is considered feasible to use in the intended application.