The master's thesis is focused on polypropylene fibres, their properties, availability, pitfalls associated with the use in practice. In the experimental part are the results of testing specimens with dispersed reinforcement fibers in varying proportions and their comparison.

This master’s thesis is divided into two parts; practical and theoretical. The theoretical part of this study describes the influence of high temperature on concrete structure and chemical, mechanical and physical changes, which take place during the exposure to high temperatures. The thesis also evaluates spalling of concrete and the methods to prevent it, as well as the function of polypropylene and cellulose fibers in the concrete. The practical part deals with design, production and testing of the cement-based concrete with the use of different fibers (polypropylene fibers and cellulose fibers). The properties and the means of applications in high temperatures are also included. The practical part also assesses the influence of high temperature on strength, porosity, visual changes of specimens, changes of surface and degradation of testing specimens due to heat loads according to normative heat curve (ISO 834) and also according to hydrocarbon curve. For clearer arrangement, the experimental tests are divided into two parts and the measured values are evaluated at the end of each part. The conclusion resumes all data obtained by testing and evaluates what is the most suitable formulation. The approach for further research is also discussed.

Los resultados del estudio que se expone en la presente tesis, tratan sobre las arcillas expansivas en “Talara”, en base a resultados obtenidos en los ensayos de laboratorio como el Análisis Granulométrico por Tamizado, ensayo de Límite Líquido, Límite Plástico e Índice de Plasticidad, ensayo de Proctor modificado y el ensayo Corte Directo. Cabe decir que dichos ensayos se realizaron tomando como punto de partida las características geológicas, geomorfológicas, geotécnicas y la evaluación de daños en las diversas estructuras de la zona como viviendas producto de la expansión y consolidación del terreno. La problemática se origina a raíz del suelo arcilloso, ya que la principal característica que puede tener ese tipo de suelo es que sea un suelo expansivo, por lo tanto, se debe tener en consideración mejorar el suelo para evitar posteriormente daños estructurales. En la investigación se describirán las principales consecuencias y factores que intervienen en el fenómeno de la expansión y el cómo enfrentar a este tipo de suelo. El presente estudio busca la mejora del suelo mediante una técnica innovadora, eco amigable y factible como es la estabilización física usando el vidrio reciclado y las fibras de polipropileno (materiales de desecho en las operaciones de la construcción), ya que en la actualidad estos dos tipos de materiales generan un impacto negativo en el medio ambiente, por lo cual se trata de reutilizar dichos materiales en el mejoramiento del suelo. El estudio se basó en una muestra de suelo medianamente expansivo, debido al registro del Límite Líquido, Límite Plástico e Índice de Plasticidad, extraído de la Urbanización Sudamérica, localizado en Talara, Piura con el fin de mejorarlo, para luego verificar el comportamiento de mejora de las propiedades de resistencia al corte del suelo. Como parte del desarrollo de la investigación se realizaron los diversos ensayos para comprobar con datos numéricos la mejora del suelo, otorgando porcentajes de sustitución con respecto al peso seco (0%, 5%, 6% y 7.5%) a la muestra en estado natural. Finalmente, se obtuvieron las mejoras de las propiedades de resistencia al corte con un porcentaje de sustitución equivalente a 5%, el cual registra las mejoras en cohesión y ángulo de fricción. / The results of the study that is presented in this thesis, deals with the expansive clays in "Talara", based on results obtained in laboratory tests such as the Granulometric Analysis by Screening, Liquid Limit test, Plastic Limit and Plasticity Index, modified Proctor test and the Direct Cut test. It is possible to say that these tests were carried out taking as a starting point the geological, geomorphological, geotechnical characteristics and the evaluation of damages in the different structures of the area as houses product of the expansion and consolidation of the land. The problem originates from the clay soil, since the main characteristic that this type of soil can have is that it is an expansive soil, therefore, it is necessary to consider improving the soil to subsequently avoid structural damage. The research will describe the main consequences and factors involved in the phenomenon of expansion and how to deal with this type of soil. The present study seeks to improve the soil through an innovative, eco-friendly and feasible technique such as physical stabilization using recycled glass and polypropylene fibers (waste materials in construction operations), since these two are currently Types of materials generate a negative impact on the environment, so it is about reusing these materials in soil improvement. The study was based on a sample of moderately expansive soil, due to the registry of the Liquid Limit, Plastic Limit and Plasticity Index, extracted from the South American Urbanization, located in Talara, Piura in order to improve it, and then verify the improvement behavior of the properties of resistance to the cut of the floor. As part of the development of the research, the various tests were carried out to verify the improvement of the soil with numerical data, granting replacement percentages with respect to dry weight (0%, 5%, 6% and 7.5%) to the sample in its natural state . Finally, the improvements of the properties of resistance to the cut with a percentage of substitution equivalent to 5% were obtained, which records the improvements in cohesion and angle of friction. / Tesis

This dissertation deals with the study of durability and degradation repair mortars for reinforced concrete structures. In its theoretical part, there are the research findings on the behavior of repair mortars exposed to corrosive environments with different exposure time and selected high temperatures. Processes occurring in repair mortars during their loading at high temperatures or when exposed to chemically aggressive environments are described, We can find recipes designed for cementitious binder based with a specific replacement using slag or fly ash in its practical part. The object of the research was to determine the durability of the proposed repair mortars, and determine their suitability for use on concrete structures, which may be exposed to a synergistic effect of chemically aggressive environments with high temperatures simulating fire.

The diploma thesis deals with self-healing of concrete composite. In the theoretical part, it represents the effect of polymer microfibers on reducing the development of cracks and on improving self-healing properties. It also describes the most commonly used types of bacteria used to enhance the self-healing process and their effect both alone and in interaction with fibers, calcium sources and absorbent additives. It also represents auxiliary additives in the form of superabsorbent polymers. In the practical part, it verifies the influence of the above elements and describes how much the self-healing of concrete has been enhanced by the use of combinations of fibers, absorbent polymers and a source of calcium in the form of calcium lactate. It also indicates whether the self-healing properties used were not improved at the expense of deteriorating the mechanical properties of the composite.