Ana Elisabete Paganelli Guimarães de Avila Jacintho

Effects of Consumption of Cement in Mechanical Properties of Lightweight Concrete Containing Brazilian Expanded Clay

Concrete is one of the oldest building materials known to humankind. From 1824, with the advent of Portland cement, concrete assumed a prominent place among the construction materials, due to large amounts of strength, durability and versatility it offered compared to other products, allowing the molding of various forms architectural. Until the early 80s, the concrete remained only as a mixture of cement, aggregates and water, however, in recent decades, due to the development of new techniques and products, the concrete has been undergoing constant changes. The concrete with lightweight aggregates have been used since the beginning of the last century, with low values of density (< 2000 kg/m3), demonstrating the great potential of using this material in several areas of construction [. With the objective of analyzing the influence of the consumption of cement in conventional concrete and light, were molded, tested and compared body-of-evidence containing two different amounts of cement consumption: a) 350 kg/m3 and b) 450 kg / m3. The results were compared with those obtained by other researchers, as well as with [ and [.

Estudo do reaproveitamento de resíduos de construção em concretos empregados na fabricação de blocos

The use of construction and demolition waste (CDR) comes as an alternative for recycling, for costs reduction and for raw material. The CONAMA Resolution 307 (National Council for the Environment) establishes that all cities should find an environmentally correct destination to CDR. In this research the mechanical properties of the concrete containing CDR were analyzed aiming its use in the production of concrete blocks. Here, increasing percentages of aggregates of CDR with the same granulometry an substitute the natural aggregate, and then concrete blocks were molded. Tests were then performed in order to determine the compression strength according to NBR 12118:2007, at ages of 14 days and 28 days. It was noticed that the values resulting from the compression strength test were also influenced by the increasing substitution of CDR percentages to the mixture. This research discusses the great potential of using this material in substitution to the natural aggregates used in the production of concrete based materials such as blocks.

Mechanical Evaluation of Concrete Containing Lightweight Aggregates

Since the invention of modern concrete, in the mid-nineteenth century until the early 80s, the concrete remained a mixture of aggregate, cement and water, with no major innovations that significantly alter the performance of its properties. But in recent decades, concrete technology has undergone tremendous development that has occurred due to the development of techniques and equipment for the study of the concrete and the use of new materials.The concrete with lightweight aggregate have been used, mainly due to the low values of density, thus demonstrating the great potential of using this material in several areas of construction [.With the objective of analyzing the influence of the consumption of cement in conventional concrete and light, were molded, tested and compared body-of-evidence containing two different values of cement consumption. The values were compared with those obtained by other researchers, as well as with the ABNT NBR 6118:2003 [ and ACI 213R-03:2003 [.

Concrete Slab Value Stream Mapping of Brazilian Residential Buildings - a Lean Construction Study Case

Sustainable research inconstruction environments has being weakening more interest for theconstruction sector, due to visible wastes during the constructive processes.In this scenario, high costs and consumptions of unnecessary materials in the work activities are inserted also, which generate waste and customer dissatisfaction.The real knowledge of this situation can be present with the Lean Thinking concepts application. The scientific initiation research identifies, from the Value Stream mapping application, the structural elements processes and all the waste detected in their observation. This study case shows how to apply the lean principles, and presents your informally application in the Brazilian Company specifically. This study has an investigative character, and considers that the company applies just a part of the Lean principles. Therefore, the paper has as objective to present the application of VSM and the preliminary sustainable analyses too.

Finite element analysis of composite concrete-timber beams

In the search for sustainable construction, timber construction is gaining in popularity around the world. Sustainably harvested wood stores carbon dioxide, while reforestation absorbs yet more CO2. One technique involves the combination of a concrete slab and a timber beam, where the two materials are assembled by the use of flexible connectors. Composite structures provide reduced costs, environmental benefits, a better acoustic performance, when compared to timber structures, and maintain structural safety. Composite structures combine materials with different mechanical properties. Their mechanical performance depends on the efficiency of the connection, which is designed to transmit shear longitudinal forces between the two materials and to prevent vertical detachment. This study contributes with the implementation of a finite element formulation for stress and displacement determination of composite concrete-timber beams. The deduced stiffness matrix and load vector are presented along to numerical examples. Numerical examples are compared to the analytical equations available in Eurocode 5 and to experimental data found in the literature.

An Alternative to Paver in Living Areas of Social Interest Housing (SIH)

The waste rubber from tire have been employed as aggregate in concrete due to their distinct characteristics, such as: less density, drainage properties improve thermal and acoustic isolation in construction, beyond final cost production reduced. This way, the substitution of part of natural aggregate by tire rubber, contributes to the natural aggregates preservation and offer an alternative for recycling this kind of waste. In view of these advantages, this study proposes the utilization of tire waste in projects of Social Interest Housing. The project has as mailing objective the construction of unfamiliar housing (vertical and horizontal) for low income families, searching a conciliation of sustainable development: social, environmental and economic. Social development means the worry with that low income family have a basic infrastructure; environmental development is to minimize the natural resources impact available; and economics is to offer new jobs and costs opportunities. The purpose of study the incorporation of this kind of waste in concretes used for interlocked pavers for floor to construct Social Interest Housing, aims to solve the problems of adequacy of this housings, offering a semi-rigid pavement that have a large use in landscaping for floor manufacturing, low maintenance and do not require specialist worker to their installation.

Application of Self-Compacting Concrete (SCC) in the Execution of Reservoir of Water

Currently, the SCC is already used in several countries and is considered a breakthrough in the building process of concrete structures, as it increases productivity, reduces the demand for labor, work in time of concreting and improves the quality of the concrete and the environment work. Innumerous investigations on SCC [,[,[,[ have been developing in order to know their behavior, improve their properties and applicability in different structural elements. This paper presents the implementation of the SCC in the execution of the base of the waters reservoir, in water treatment station.

Short steel and concrete columns under high temperatures

The growing demand for knowledge about the effect of high temperatures on structures has stimulated increasing research worldwide. This article presents experimental results for short composite steel and concrete columns subjected to high temperatures in ovens with or without an axial compression load, numerically analyzes the temperature distribution in these columns after 30 and 60 minutes and compares them with experimental results. The models consist of concrete-filled tubes of three different thicknesses and two different diameters, and the concrete fill has conventional properties that remained constant for all of the models. The stress-strain behavior of the composite columns was altered after exposure to high temperatures relative to the same columns at room temperature, which was most evident in the 60-minute tests due to the higher temperatures reached. The computational analysis adopted temperature rise curves that were obtained experimentally.

Conventional concrete with addition of recycled rubber tires: Study of the mechanical properties

The world is now pressing for decreasing emissions of greenhouse gases, the reduction and possible revocation of culling and disposal of materials resulting from manufacturing processes that pollute and degrade the environment. Among these problems unused tires has become a major problem for the environment due to years of provisions incorrect. On motion of reuse, recycling and waste disposal, construction has become a major partner of the other production areas to reduce several types of industrial wastes by reusing these materials, the introduction of these materials in construction products civil, replacement of traditional materials and various other ways. Have produced different concrete mixtures without and with different percentages of rubber tires. The results indicate a clear loss of strength both in compression as in tension. Key words: alternative materials, materials and components in construction, materials recycling.

Brazilian Geological Sandstone Characterization and its Utilization as Aggregate in Structural Concrete

The sandstone extraction is an essential activity to the production of specific products. It is employed in the civil construction sector. However, there is still a deficiency in physical and geological characterization. This research develops two experiments in the sandstone matrix located in São Carlos region (City of São Paulo State – Brazil). The first experiment is related to the geological aspect of the specific sandstone. It identified the geographic location and investigated the porosity and absorption rates of the Brazilian sandstone rock, besides verifying its compressive strength. The purpose was to identify and evaluate possibilities of sandstone use in the structural concrete composition. The second experiment tested the concrete strength with this aggregate. Some quantities of crushed sandstone were used as fine aggregate in the manufactured concrete. The experiments presented sandstone properties and sandstone aggregate possibilities in concrete composition. The present study is a result of an undergraduate project, aiming to contribute with new information on the Brazilian sandstone characterization and concrete strength application with the sedimentary aggregate. This work showed some possibilities to use this type of yellow and red sandstone as aggregate.