El objetivo del presente trabajo ha sido diseñar un Plan de negocio para la implementación de una planta de fabricación de productos prefabricados para el sector construcción en la ciudad de Chiclayo. Covipre SAC es una empresa familiar que opera en Lima desde el año 2005 y está dedicada a la fabricación de productos prefabricados orientados a los sectores construcción, saneamiento y minería. El crecimiento anual del sector construcción en Chiclayo, equivalente al 11,38%, representa uno de los índices más altos entre las ciudades de la zona norte del país, lo cual constituye una oportunidad para la expansión de la empresa. Para el logro del objetivo previsto se han realizado el análisis y el planeamiento estratégico; se han diseñado: el plan de marketing, el plan de operaciones y la estructura organizacional de los recursos humanos y el plan económico-financiero. Se ha determinado que el negocio es viable en un horizonte de 10 años; por cuanto, se han obtenido flujos positivos a partir del cuarto año de operaciones. Es así que, en un escenario moderado, el VAN asciende a S/. 931 624,00 y la TIR de 46,10%. La inversión para el plan de negocio asciende a S/. 813 969,00. / The objective of this work has been to design a Business Plan for the implementation of a manufacturing plant of prefabricated products for the construction sector in the city of Chiclayo. Covipre SAC is a family business that operates in Lima since 2005 and is dedicated to the manufacture of prefabricated products oriented to the construction, sanitation and mining sectors. The annual growth of the construction sector in Chiclayo, equivalent to 11.38%, represents one of the highest rates among the cities in the northern part of the country, which constitutes an opportunity for the expansion of the company. To achieve the planned objective, the analysis and strategic planning have been carried out; have been designed: the marketing plan, the operations plan and the organizational structure of human resources and the economic-financial plan. It has been determined that the business is viable in a horizon of 10 years; since positive flows have been obtained from the fourth year of operations. Thus, in a moderate scenario, the NPV amounts to S /. 931 624.00 and the IRR of 46,10%. The investment for the business plan amounts to S /. 813 969.00. / Trabajo de investigación

The aim of the dissertation is to understand the formation and development of the market for construction materials (cement, lime and bricks) in Cisleithania and Czechoslovakia. Emphasis is placed on market trends (changes in consumer habits, new technologies), market monopolisation, state interventionism and institutional changes in business activities (capital inputs of the banking sector and the spread of capital companies). The dissertation contentrates on the basic market conditions and market structure, as well as the strategies of the market players. The market performance (the impacts of the construction materials industry on the Cisleithanian and Czechoslovak economies) is also included. The research is limited by the period of the so-called Great Depression (construction materials began to be produced on the industrial basis) and the turn of 1938/1939, marking the instrumentalization of the Czech lands in favor of the German economy. The dissertation is based on methods of industrial economics (Structure-Conduct-Performance paradigm), economics, economic geography and traditional methodology of economic history (especially business history, hermeneutic and statistical method).

<p>Superabsorbent polymer (SAP) hydrogel particles have been used as internal curing agents in concrete mixes as they are capable of absorbing and subsequently releasing large amounts of water. This reduces autogenous shrinkage during early stages of hydration. The size, shape, and composition of the hydrogel particles can be controlled during the synthesis, hence providing the opportunity to custom synthesize these internal curing agents to elicit desired structure-property relationships. Utilization of optimized dosage and formulation of SAP has the potential to improve the microstructure, durability, and strength of internally cured concrete. </p> <p>The first study focuses on the synthesis and application of novel composite hydrogel particles as internal curing agents in cementitious mixes. Composite polyacrylamide hydrogel particles containing two different amorphous silica–either nanosilica or silica fume–were used to investigate whether the internal curing performance of hydrogel particles could be enhanced. The dosage and type of silica, crosslinker amount were varied to identify the composite polyacrylamide hydrogel particle composition that provides optimum benefits to internally cured cementitious systems. The synthesized hydrogels were characterized by means of absorption capacity tests, compositional and size analysis. The beneficial impacts of the addition of composite hydrogels on cement paste microstructure are highlighted, including the preferential formation of cement hydration products (such as portlandite) within the hydrogel-induced voids that appeared to be influenced by the composition of the hydrogel particles. The interrelationship between extent of hydration, size of hydrogel voids, and void-filling with hydration products was found to strongly influence mechanical strength and is thus an important structure-property relationship to consider when selecting hydrogels for internal curing purposes. This study informs the design of composite hydrogel particles to optimize performance in cementitious mixes. Additionally, it provides a novel means of incorporating other commonly used admixtures in concrete without facing common challenges related to dispersion and health hazards.</p> <p>The second study focuses on the utilization of two retarding admixture-citric acid and sucrose-to custom synthesize composite polyacrylamides to investigate whether the composite hydrogels could delay hydration of cement paste. Isothermal calorimetry analysis results showed that composite sucrose-containing polyacrylamide hydrogel particles were successfully able to retard main hydration peak of cement paste, beyond the retardation capabilities of the pure polyacrylamide hydrogels. Thus, this study provides avenues of exploring the utilization of common admixtures to formulate novel composite hydrogels that imparts specific properties to cementitious systems.</p> <p>In another study, SAP formulated by admixture industries were used to investigate the feasibility of internal curing of bridge decks and pavement patches with SAP particles. The microstructure and early age hydration properties of SAP-cured cementitious systems were studied. Mitigation of microcracks in the matrix, along with portlandite growth in SAP voids, were observed in SAP-cured mortars. Presence of SAP also mitigated autogenous shrinkage and improved early age hydration as observed by isothermal calorimetry analysis. This thesis highlights some of the beneficial impacts of SAP-cured cementitious systems, and the potential to harness those benefits in large-scale applications of SAP-cured concrete.</p> <br>

No / The influence of loose plant leaves on the acoustic absorption of a porous substrate is experimentally and numerically studied. Such systems are typical in vegetative walls, where the substrate has strong acoustical absorbing properties. Both experiments in an impedance tube and theoretical predictions show that when a leaf is placed in front of such a porous substrate, its absorption characteristics markedly change (for normal incident sound). Typically, there is an unaffected change in the low frequency absorption coefficient (below 250 Hz), an increase in the middle frequency absorption coefficient (500-2000 Hz) and a decrease in the absorption at higher frequencies. The influence of leaves becomes most pronounced when the substrate has a low mass density. A combination of the Biot's elastic frame porous model, viscous damping in the leaf boundary layers and plate vibration theory is implemented via a finite-difference time-domain model, which is able to predict accurately the absorption spectrum of a leaf above a porous substrate system. The change in the absorption spectrum caused by the leaf vibration can be modeled reasonably well assuming the leaf and porous substrate properties are uniform.

No description available.

Percent within limits (PWL) is a commonly used quality control/quality assurance measure of highway pavement materials and construction, and it is a popular index for adjusting pay factors. However, PWL is based on the assumption of normal distribution of quality characteristics (e.g., concrete compressive strength and asphalt air voids). Skewness and kurtosis, which are common forms of statistical nonnormal distributions, can potentially bias the acceptance pay factor calculations. To examine this potential pay bias, simulations were performed to investigate the magnitude and the direction (overestimation or underestimation) of pay factor calculations. The study revealed that for both one-sided and two-sided specification limits, bias in pay factors not only did vary in magnitude but also reversed in direction over various ranges of PWL. These analyses showed that for a one-sided upper specification limit, on average, a positive skewness and kurtosis can underestimate the pay factor of an acceptable quality level population by 0.90%, and overestimates a rejectable quality level population by 3.8%. This leads to falsely penalizing acceptable products and rewarding bad products. The same was true for two-sided limits, which again varied based upon the percent of defective materials at the tails of the distribution. This is a very important issue because these biases in pay factors can easily upset the relative profit margins of the contractor. Furthermore, this may not be easily detectable without a detailed and sophisticated analysis as outlined in this paper. For multiple quality characteristics based pay factors, analyses showed that the combined magnitude of these biases was not linearly cumulative. Findings of the study indicate that bias in pay was higher for lots with fewer sublots and higher skewness and kurtosis.

El presente proyecto de investigación consiste en la adición de dos sustancias tales como la nanoplaqueta de grafeno (NPG) y aserrín al concreto para la producción de adoquines de alto tránsito para luego verificar su resistencia a compresión, resistencia a la flexión y resistencia al desgaste por abrasión. Se elaboraron 135 adoquines de concreto para una resistencia de f’c = 420 kg/cm2. Se formaron 4 grupos de 27 adoquines con diferentes combinaciones de 0.05% NPG - 1.0% A, 0.05% NPG - 1.5% A, 0.10% NPG - 1.0% A, y 0.10% NPG - 1.5% A; las cuales estas sustancias serán sometidas primero a análisis previos tales como el análisis químico del aserrín y la dispersión de la nanoplaqueta de grafeno para posteriormente adicionarlos a la mezcla. Los resultados mostraron una alta resistencia en la combinación de 0.05% NPG - 1.0% A y 0.05% NPG - 1.5% A, son superiores al adoquín patrón en 9.58% y 3.73% respectivamente. Con respecto a la resistencia a la flexión el que presento mejores resultados es la combinación de 0.05% NPG - 1.5% A, cumpliendo con la norma. En la prueba de resistencia al desgaste por abrasión es variable debido a diversos factores como el agregado, las adiciones y/o los agrietamientos de la superficie del adoquín. / The present research project consists of the addition of two substances such as graphene nanoplatelet (NPG) and sawdust to concrete for the manufacture of high traffic pavers to subsequently verify their resistance to compression, bending and abrasive wear. A total of 135 concrete pavers with a strength of f'c = 420 kg/cm2 were manufactured. Four groups of 27 pavers were formed with different combinations of 0.05% NPG - 1.0% A, 0.05% NPG - 1.5% A, 0.10% NPG - 1.0% A, and 0.10% NPG - 1.5% A; these substances were first subjected to preliminary analyses such as chemical analysis of sawdust and dispersion of graphene nanoplatelet and then added to the mix. The results showed high strength in the combination of 0.05% NPG - 1.0% A and 0.05% NPG - 1.5% A, higher than that of the standard paver by 9.58% and 3.73%, respectively. In terms of flexural strength, the best results were obtained with the 0.05% NPG - 1.5% A combination, which complies with the standard. In the abrasion wear resistance test, it is variable due to various factors such as aggregate, additions and/or cracking of the paver surface.

En las últimas precipitaciones suscitadas en nuestra región Lambayeque, específicamente en el distrito de Mórrope, nos alarmado, más aún en el fenómeno Yaku, registrado en este año. Frente a ello, esta investigación tuvo por objetivo mejorar la resistencia del adobe a efectos de las lluvias e inundaciones, utilizando el Yeso y la Poña de Algarrobo que actualmente se incinera. Para ello, primero se conoció las propiedades y composición de los materiales y elementos a adicionar; posteriormente, se obtuvo una muestra patrón de adobe; después de ello, se obtuvieron los porcentajes óptimos tanto para Yeso y Poña de Algarrobo y finalmente, se procesaron y analizaron los datos para cuantificar los resultados. Dentro de nuestros resultados se obtuvieron que adicionándole 6% Poña de Algarrobo y 9% de Yeso al adobe patrón, la resistencia a la compresión se incrementa en 59.54%, la tracción en 15.85%, la flexión en 15.69%, la compresión de murete en 28.40%, la tracción diagonal de murete en 26.09%, la tracción del mortero en 60.00%, la erosión en 58.05%, la succión se redujo la desintegración parcial, la inmersión se redujo la desintegración total y en la inundación simulada aumentó la resistencia a la absorción y capilaridad. Por lo tanto, se ha llegado a concluir que al adobe tradicional incorporándole 6% de Poña de Algarrobo y 9% de Yeso, mejora sus propiedades físicas y mecánicas incrementando la resistencia al agua. / In the latest rainfall in our Lambayeque department, specifically in the Mórrope district, we were alarmed, even more so in the Yaku phenomenon, registered this year. Faced with this, this research aimed to improve the resistance of adobe to the effects of rains and floods, using the Yeso and the Poña of Algarrobo that is currently incinerated. For this, first the properties and composition of the materials and stabilizers were known; subsequently, a standard sample of adobe was obtained; after that, the optimal percentages were obtained for Yeso and Poña of Algarrobo and finally, the data was processed and analyzed to quantify the results. Among our results, we obtained that by adding 6% Poña de Algarrobo and 9% Yeso to the standard adobe, the resistance to compression increases by 59.54%, the traction by 15.85%, the bending by 15.69%, the compression of the wall by 28.40 %, diagonal wall traction in 26.09%, the traction of mortar by 60.00%, erosion in 58.05%, suction reduced partial disintegration, immersion reduced total disintegration and in simulated flooding increased resistance to absorption and capillarity. Therefore, it has been concluded that incorporating 6% Poña de Algarrobo and 9% Yeso to traditional adobe increases its physical and mechanical properties, increasing its resistance to water.

La presente investigación tiene como objetivo general comparar cuál de las dos fibras tanto CFRP (polímero reforzado con fibra de carbono) o GFRP (polímero reforzado con fibra de vidrio) sería la más adecuada para el incremento de la resistencia de las columnas y vigas antes sismos de magnitudes 8.1 y 6.6 en la escala de Richter, necesario para poner en servicio la I.E N°440 Las Flores de la Pradera, que cuenta con 3 pabellones de las cuales el pabellón A-A, B-B son de un nivel con un área de 189.96m2 (7.90m x 24.01m), de 200.41m2 (7.90m x 25.37m), el pabellón C-C es de dos niveles de 36.46m2 (5.58m x 6.34m). El ser aplicadas en las infraestructuras esenciales que han logrado brindar rigidez, seguridad, durabilidad, eficacia, pero frente a la postura del tiempo útil o limitaciones de funciones extremas que han llegado a poner en riesgo su estabilidad. Los polímeros reforzados con fibra de carbono y vidrio han sido un material de solución esencial, definiéndola como una técnica restauradora que, junto a sus propiedades, características y su uso que se han dado en diferentes Áreas de Infraestructuras. Finalmente, se llegó a concluir en la investigación que cumplió el incremento de las resistencias de las vigas a flexión y corte demostrando como el reforzamiento estructural con los polímeros reforzados más adecuado que cual otro material y lo más esencial es que no modifica la estética de la arquitectura en gran magnitud. Pero lo más con una diferencia de que la fibra de carbono (CFRP) no requiere tantas capas como la fibra de vidrio ya que tiene un mejor desempeño en deformación vs esfuerzo a tensión. / The general objective of this research is to compare which of the two fibers, CFRP (carbon fiber reinforced polymer) or GFRP (glass fiber reinforced polymer), would be the most suitable for increasing the resistance of columns and beams before earthquakes. of magnitudes 8.1 and 6.6 on the Richter scale, necessary to put into service the I.E N ° 440 Las Flores de la Pradera, which has 3 pavilions of which pavilion A-A, B-B are one level with an area of 189.96m2 (7.90m x 24.01m), 200.41m2 (7.90m x 25.37m), pavilion C-C has two levels of 36.46m2 (5.58m x 6.34m). Being applied in essential infrastructures that have managed to provide rigidity, security, durability, efficiency, but in the face of the useful time posture or limitations of extreme functions that have come to put their stability at risk. Carbon and glass fiber reinforced polymers have been an essential solution material, defining it as a restorative technique that, together with its properties, characteristics and its use that have been given in different Infrastructure Areas. Finally, it was concluded in the investigation that the increase in the resistance of the beams to bending and shear was achieved, demonstrating how the structural reinforcement with reinforced polymers is more adequate than any other material and the most essential thing is that it does not modify the aesthetics of the structure. architecture in great magnitude. But the most important difference is that carbon fiber (CFRP) does not require as many layers as fiberglass since it has a better performance in deformation vs. tensile stress.

La presente investigación tiene como objetivo evaluar la influencia de la incorporación de agregado grueso reciclado (AGR) y cenizas de aserrín (CDA) en la elaboración de adoquines de concreto para tránsito ligero, para ello primero se realizó la caracterización de los agregados naturales y reciclado y se clasificó las cenizas de aserrín; posteriormente como primera etapa de demostración se determinó el porcentaje óptimo de cenizas, para ello se realizó el diseño de mezcla para la muestra patrón y con adiciones de 5%, 10% y 15% de CDA, de donde mediante los ensayos físico mecánicos se obtuvo que el porcentaje óptimo es el 5%, dado que mejoran las propiedades de los adoquines, luego se realizó la segunda etapa donde se elaboraron especímenes con el porcentaje óptimo de ceniza determinado y el 100% de agregado grueso reciclado, a los cuales como en la primera etapa se le realizó los mismos ensayos donde se determinó que la incorporación del 100% de AGR hace que disminuya la resistencia a la compresión y las otras propiedades se mantienen dentro de los parámetros permitidos. / The objective of this research is to evaluate the influence of the incorporation of recycled coarse aggregate (AGR) and sawdust ash (CDA) in the elaboration of concrete paving stones for light traffic, for which the characterization of natural and recycled aggregates was first carried out. and sawdust ash was classified; Subsequently, as the first demonstration stage, the optimum percentage of ashes will be reduced, for which the mixture design was carried out for the standard sample and with additions of 5%, 10% and 15% of CDA, from which, through the physical-mechanical tests, it was obtained. that the optimal percentage is 5%, since the properties of the paving stones improve, then the second stage was carried out where specimens were made with the optimal percentage of determined ash and 100% recycled coarse aggregate, to which, as in the In the first stage, the same tests were carried out where it was established that the incorporation of 100% of AGR causes the compressive strength to decrease and the other properties to remain within the permitted parameters.