Libre competencia en agua, energía y transporte: La experiencia de América Latina entre 2010 y 2020 (original) (raw)
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THERMAL PERFORMANCE & FIRE RESISTANCE OF AUTOCLAVED AERATED CONCRETE EXPOSED HUMIDITY CONDITIONS
Autoclaved Aerated Concrete (AAC) is also being produced for many years, there are still some points that need to be clarified. One of these points needs to know is humidity intrusion effects on AAC members in areas with high relative humidity levels of Mediterranean climates which are important in durability and insulation properties of AAC. Therefore, some tests on mechanical and physical properties of ACC concrete carried out. These include thermal insulation and fire resistance tests under different level of humidity ACC blocks. According to the test results; increasing in humidity condition inside the chamber during heating procedure under steady state condition, caused increasing in average temperature change on outside surface of AAC wall. AAC losses its mass and mechanical properties subjected to the high elevated temperature above 500°C.
Effects of the Exposure to Fire and Fire Extinguishing Agents on the Behavior of Building Materials
International Journal of Advanced Trends in Computer Science and Engineering, 2020
This study investigates the effect of elevated temperatures on concrete mixes used in Jordan for building purposes; for its mechanical properties; where compression, tensile and impact tests were conducted for the mentioned materials. Additionally, a thermal conductivity test was carried out for thermal properties at ambient temperatures. Standard methods for the examination of concrete were adopted for all conducted measurements. Moreover, a comparison has been drawn between the behavior of normal strength concrete and the behavior of high strength concrete. This research study also examines the effect of the use of water and dry chemical powder extinguishers on the mechanical properties of concrete at elevated temperatures. Results have shown that a loss of concrete compressive, tensile, and impact strengthsare noticed with increasing temperatures and heating duration. The presence of additives in concrete mixtures increases the strength of both high strength concrete and normal strength concrete. Furthermore, the results have shown that the use of water and dry chemical powder as extinguishing agents and did not deteriorate further the compressive strength of the high strength concrete and normal strength concrete.
The current research studied the effect of elevated fire temperature and cooling regime on the fire resistance of self-compacting concrete (SCC) and normal concrete (NC). Both concretes were exposed to elevated degrees of fire temperature of 200, 400, 600 and 800 °C. In addition, the temperature was maintained at 800 °C while the exposure durations have been increased to 15, 30, 60 and 120 minutes. After that the samples were cooled to room temperature using three different cooling regimes namely; air cooling, CO2 powder cooling and water cooling. Reductions in both compressive and tensile strength results along with the extent of spalling were examined. The effect of fire and cooling regime on both porosity and absorption capacity of SCC and NC were also investigated. The results indicated that residual compressive and tensile strengths of SCC are generally higher than those of NC. In other words, elevated fire temperature is more damaging to the NC compared with SCC. Same has been confirmed by the obtained results of spalling which were found to be higher for NC compared with those of SCC. The results also indicated that adopting CO2 powder as a cooling regime provided the least extent of damage to both NC and SCC concretes while water cooling regime provided the greatest damage. It is worth mentioning that the incorporation of polypropylene fibre improved the fire resistance of concrete regardless of the concrete type and cooling regime. Increasing the dosage of self-compacting admixture did not significantly affect the mechanical properties and fire resistance of SCC.
Influence of curing time on the fire performance of solid reinforced concrete plates
Influence of curing time on the fire performance of solid reinforced concrete plates, 2020
j m a t e r r e s t e c h n o l. 2 0 2 0;9(2):2506-2512 w w w. j m r t. c o m. b r Spalling Fire resistance Non-load bearing wall system a b s t r a c t When reinforced concrete elements are subjected to high temperatures, such as in a fire, they are susceptible to physical and chemical changes that cause spalling, thereby undermining their performance under such conditions. It is known that the age and the internal moisture content of concrete are factors that contribute to this event, but the intensity of spalling is not yet a consensus. This study aimed to assess the influence of age and internal moisture on the performance of concrete walls at high temperatures. Therefore, 6 real-scale walls were built with dimensions of 3.15 × 3.00 m, with the same composition of concrete, for tests in a vertical furnace under the ISO 834 curve, for ages of 7, 14, 28, 56, 84 and 830 days. Moisture was measured as per the electrical resistivity of concrete. It was noted that walls with ages above 84 days showed no spalling whatsoever, due to the internal moisture of concrete. The most severe spalling took place at 14 days, thus evidencing that pore interconnectivity and hydrated cement crystallization can contribute as well.
Experimental Investigation on Effect of Fire on Properties of Concrete with the Use of Admixture
Damage due to fire can cause in terms of loss of life, homes and livelihoods. One of the advantages of concrete over other building materials is its inherent fireresistive properties. However, concrete structures must still be designed for fire effects. Structural components must still be able to withstand dead & imposed loads without collapse even though the rise in temperature causes a decrease in the strength & modulus of elasticity for concrete. Fire resistance is measured in terms of structural stability, structural integrity and insulation. This Experimentation involve the study of residual strength in concrete after exposure to elevated temperatures for concrete in which coarse aggregate replace with (20%, 40% and 60%) blast furnace slag and additional 1% steel fiber is added to increase the tensile strength of concrete. The effect of elevated temperature at 200, 400, 600, 800, 1000 and 1200 for the exposure of 1hours are studied. Compressive strength, split tensile strength and flexural strength are obtained after exposure to elevated temperature. Also investigated colour change, area of colour spot, width of crack, types of crack, of samples when exposed to fire at different temperatures and exposure times.
International Journal of Safety and Security Engineering, 2020
The traditional building in Iraq characterised by the using of a certain number of finishing's in external façades like cement plastering, limestone and perforated yellow brick because the raw materials of manufacturing are available locally. Fire spread through the facades is widely recognized as one of the fastest pathways of fire spreading in the buildings, so the appropriate choose of highly performance finishing material against fire will be potentially the main factor in controlling the fire and suppressed it. This study uses computer modeling and fire simulation technology of Pyrosim, FDS and smoke view to compare the difference between the performance of some traditional finishing materials like cement plastering, limestone and perforated yellow brick with the ACPs and their speed to transfer fire from floor to floor if used in multi storey buildings. The study highlighted that traditional finishing materials are more efficient than modern cladding materials and that the...
Agro-Industrial Aerated Concrete: Insulation for Thermal Reduction in Building
This paper presents a comparative study aiming in investigate the heat impact for different percentages of Palm Oil Fuel Ash(POFA) for agro-industrial aerated concrete based on their thermal behaviors.In aerated concrete production , aluminum powder is used to create pores which lead to thermal insulation property. Besides that, the bottom ash has being used as sand replacement and performance of POFA replacing binder content at percentages of 0, 10, 20 and 30 by weight has being identify. In order to investigate the thermal performance on the building material, surface temperature sensors, data logging systems together with Infrared thermometric were used respectively. Thermal images will simply rectify the behavior of outdoor surface temperature by having the " heat impact ". The results indicate that 30 per cent of POFA aerated concrete has the better improvement in thermal conductivity and had the capability to absorb and released the heat in shorter time. The study proved that the higher the time lagged hence lower the thermal insulation properties.
Thermo-Physical, Mechanical and Hygro-Thermal Properties of Newly Produced Aerated Concrete
Journal of Materials Science and Surface Engineering, 2021
The main objective of this study is to characterize a material, non-autoclaved aerated concrete, referred to as "foamed concrete", newly produced in Burkina Faso. This study made it possible to determine some thermo-physical, mechanical and hygro-thermal properties of foamed concrete. The material was obtained by making a mixture of cement, sand, water and a foaming agent.The tests were carried out with five types of samples having densities between 600 and 930 kg/m 3 and a water content ranging from 22 to 35%. The experimental results obtained show that the studied foamed concrete has a thermal conductivity ranging from 0.05 to 0.2 W/m.K and compressive strength is between 1.2 to 3.4 MPa. The dynamic Young's modulus is between 1.18and 3.1 GPa and the porosity is varying from 55.60 to 72.36%. Analysis of the results show that the incorporation of the foam in the mortar made it possible to have a more insulating material and acceptable mechanical properties for sustainable construction.