The reinforcement of soils is the technique that geotechnical engineers currently use to improve the shear strength and bearing capacity parameters, especially when the land available for the execution of a project is not able to withstand the structural loads to which it is subjected. One of the techniques, used for this purpose since ancient times, is the incorporation of fibers into the soil matrix; however, great interest in its study has only begun in the last two, mainly because it constitutes a low-cost and environmentally friendly alternative. In this paper, a brief bibliographic review is presented on seven of the natural fibers that are currently used in order to improve the mechanical behavior of expansive clay soils (bamboo, jute, coco, palm, sugar cane bagasse, rise husk, and sawdust). It can be concluded that in many cases, the addition of certain amounts of natural fibers increases the parameters of resistance to the cutting of soils.

En el presente trabajo se analiza el estudio experimental de zapatas aisladas, evaluando el efecto de la ceniza de bagazo de caña de azúcar (CBCA) como sustituto en diferentes porcentajes en el cemento, esto con el objetivo de evaluar las variaciones en la resistencia a la compresión, además se analizan las fallas que presenta la zapata aislada. La elaboración del espécimen consta de la caracterización de los agregados que conforman la mezcla de concreto asimismo de la ejecución de las sustituciones en el cemento en un (0%, 3%, 5%), sin refuerzo y (0%) con refuerzo. El diseño es ejecutado por el método del ACI 211.1 por volúmenes absolutos, para una resistencia estimada de 250 kg/cm2, una vez elaborados los especímenes de concreto se introdujeron en el suelo arcilloso a una profundidad de 0.50 m. del nivel de piso terminado, donde permanecieron por 50 y 112 días. posteriormente se ejecuta la prueba de resistencia a la compresión mediante la normativa NMX-C-083-ONNCCE-2014. donde se observan resistencias mecánicas inferiores al valor del concreto control y la falla más predominante es la de tipo compresión, sin embargo, se recomienda especímenes del 5%, debido a que su comportamiento es similar al concreto control.

Energy production in constructed wetlands is a little-known field, as is the operation of vertical partially saturated constructed wetlands (VPS-CWs) that promote both aerobic and anaerobic microbial interactions. By doing so, bacterial degradation is increased, becoming the main mechanism of pollutant removal in constructed wetlands (CWs). For the first time, the generation of bioelectricity, together with the production of ornamental plants in vertical partially saturated constructed wetlands during the treatment of domestic wastewater, was evaluated. Six VPS-CW systems functioned as bioelectricity generators, where the systems were filled with red volcanic gravel and activated carbon as anode and cathode. Three systems were planted with Zantedeschia aethiopica and three with Canna hybrids plants. The development was measured through mother plants and shoots produced every 60 days. The input and output of each VPS-CW was monitored using control parameters such as BOD5, phosphates (P-PO4), and total Kjeldahl nitrogen (TKN). Bioelectricity, power, voltage, and current measurements were performed every 15 days for a period of 7 months. It was found that the VPS-CWs used as biobatteries in combination with the use of domestic wastewater as a substrate improved the development of the two evaluated plant species and stimulated growth and germination of new shoots. No significant differences were found between the different treatments (p ≤ 0.05). Likewise, an average efficient removal of BOD5 (98%) for both systems without statistical differences was observed (p ≤ 0.05), but for TKN and P-PO4, significant differences (p ≤ 0.05) were found between systems planted with Z. aethiopica (TKN: 65%; P-PO4: 20%) and Canna hybrids (TKN: 69%; P-PO4: 27%). This method of water treatment and bioelectricity production with Canna hybrids was an efficient system that generated a great electric current (140 mA/m2), voltage (750 mV), and electric power (15 mW/m2), compared with those observed in systems with Z. aethiopica (60 mA/m2, 500 mV, 9 mA/m2).

A frequent problem in Geotechnics is the soils with inadequate physical-mechanical properties before the efforts to which they will be subjected by the constructions, incurring cost overruns caused by their engineering improvement. The need to improve the engineering properties of soils is not recent, currently observing that the most common alternatives are binders such as cement and lime. The climate change observed in recent decades and the uncontrolled emission of greenhouse gases have motivated Geotechnical and Geoenvironmental researchers to seek mechanisms for soil reinforcement from a more sustainable and environmentally friendly approach by proposing the use of recycled and waste materials. An alternative is natural fibers, which can be obtained as waste from many agro-industrial processes, implying their high availability and low cost. Sawdust as a by-product of wood processing has a rough texture that can generate high friction between the fiber and the matrix of the soils, leading to a significant increase in its shearing strength and bearing capacity. This concept of improving the properties of soils using natural fibers distributed randomly is inspired by the natural phenomenon of grass and/or plants that when growing on a slope can effectively stabilize a said slope.