The objective of this research was to determine the influence of the percentage of rice husk ash (CCA) and the concentration of the alkaline activator on the removal of chromium ions from geopolymer filters based on metakaolin (MK), due to the high toxicity generated by the chromium on health and the environment. The geopolymer was prepared by mixing activated rice husk ash at different percentages (0% , 10%, 20%, 30%) with kaolin at different molarities of sodium hydroxide (10M, 12M, 14M); subsequently, spheres of 4 mm in diameter were formed; was placed in the oven at a temperature of 110°C for 24 hours after 1 day of cooling, the same samples were placed in the oven at a temperature of 900°C for a time of half an hour to achieve sintering of the geopolymer. The results obtained through the adsorption process indicate that the highest percentage of chromium (VI) removal is achieved when the geopolymer is made up of metakaolin with 30% rice husk ash with an alkaline activator concentration (NaOH) of 14M with a time of 3 hours, being 54.42% the percentage of remo va l of chromium VI ions. This study concludes that the higher the percentage of CCA and the higher the molarity of the alkaline activator (NaOH), the higher the percentage of removal of chromium ions.

Researchers are continuously seeking to develop new materials to protect against inclement weather and thus optimize energy efficiency in housing. This research aimed to determine the influence of corn starch percentage on the physicomechanical and microstructural properties of a diatomite-based porous ceramic. The starch consolidation casting technique was applied to fabricate a diatomite-based thermal insulating ceramic with hierarchical porosity. Diatomite mixtures with 0%, 10%, 20%, 30%, and 40% starch were consolidated. The results show that starch content significantly influences apparent porosity, and this, in turn, influences several parameters, such as thermal conductivity, diametral compressive strength, microstructure, and water absorption of diatomite-based ceramics. The porous ceramic processed by the starch consolidation casting method corresponding to the mixture of diatomite with 30% starch obtained the best properties, with a thermal conductivity of 0.0984 W/m·K, an apparent porosity of 57.88%, a water absorption of 58.45%, and a diametral compressive strength of 35.18 kg/cm2 (3.45 MPa). Our results reveal that the diatomite-based ceramic thermal insulator obtained by starch consolidation is effective for use on roofs to improve thermal comfort in dwellings located in cold regions.

In this research, it is proposed to stabilize the soil surrounding the water and sewerage networks with sodium chloride to avoid the formation of holes produced by leaks that cause fines dragging that weaken the soil and cause collapse, a phenomenon known as piping or internal erosion. The soil was characterized by the SUCS and AASHTO methods, carrying out the tests of sieving granulometry, sedimentation granulometry, consistency limits, and natural humidity. The compaction test was carried out by means of the modified Proctor test on the standard sample and the samples with the addition of NaCl, to obtain the maximum dry density a nd humidity, using them as a reference in the unconfined compression, CBR, and permeability tests. For each test, 4 repetitions were carried out for the standard samples and for the samples that were added with NaCl whose doses were 1.5, 3, and 4.5% by weight. At the end of the tests, it was determined that the type of standard soil is sandy clay soil with medium plasticity, classifying it as a "CL" soil according to the SUCS method and "A-6" for the AASHTO metho d . By adding 1.5% sodium chloride to clay soil, the best properties are obtained; having a 315% increase in the CBR index, an 82% increase in unconfined compressive strength, and a 21% reduction in permeability.

The objective of this research was to find the optimum mixing ratio of kaolin-quartz-feldspar concerning the possibility of obtaining porcelain ceramics with the highest strength and density and the lowest water absorption. Statistica 12 software was used to optimize the mix design using the simplex centroid method. Ten compositions were prepared according to the mentioned design, formed by extrusion in the form of cylindrical specimens in triplicate, after sintering the specimens in a gas oven at a temperature of 1280°C, their apparent bulk density and water absorption properties were determined using an immersion method and diametral compressive strength in a 50 kN load press at a sp eed of 1 m m /m in.Contour plots were constructed to determine the optimal mixing ra tio for the three investigated properties. From the analysis of these graphs, it was concluded that the triaxial paste with the highest resistance and density and the lowest water absorption is that of 75% kaolin, 5% quartz, and 20% feldspar. Finally, a d ilatom etric study was carried out for a mixture with that mixing ratio fro m ro om temperature to 1300°C to monitor its linear thermal expansion with temperature.

This research evaluates the effect of the addition of sediments from irrigation water clarification, rice husk ash (CCA), and calcareous scallop residue (RCCA) in the stabilization of sandy soils to improve access roads to agricultural areas. For this, the physical properties, microstructures, and phase analysis were determined by hydrometry, scanning electron microscopy, a nd Xray diffraction respectively. Five soil-sediment mixtures were evaluated at different percentages by means of the California Bearing Ratio (CBR) test. Then, to determine the best dosage of stabilizers on the best mixture obtained previously, 4 samples were tested at different proportions of CCA and RCCA by means of the CBR and triaxial compressive strength tests. The results showed that the mixture of 60% soil -40% sediment presents an increase in the CBR index of 42 compared to the natural soil (CBR of 6) and this mixture reaches a CBR index of 94 when 6% CCA and 1.5% RCCA are added. In addition, according to the Triaxial test, an undrained cohesion of 796.33 kPa was obtained. Finally, it is concluded that the soil-sediment combination showed an increa se of 57% in its support capacity when mixed with minimum percentages of CCA and RCCA, an increase in stiffness and undrained cohesion was also observed. The physical-chemical stabilization presented was applied in the design of the thickness of the rolling layer of the access roads to agricultural areas incorporated by the ChavimochicProject.