Papers by Keyword: Porous Concrete

Abstract: Sound-absorbing acoustic materials are usually made of special materials which are sometimes expensive and prone to fire and do not have sufficient strength. This research offers materials that have sufficient properties for the above problems, namely by using porous concrete. This study aims to calculate the absorption values of porous concrete values. Porous concrete is concrete which does not use sand to forms a void in concrete that also might be used as a sound absorbent. The concrete then is substituted with silica fume to reach more compressive strength. The value of absorption was measured by the impedance method of two microphones. The sample was put in a tube with a diameter of 10 cm and a height of 5 cm. The proportion of samples using American NRMCA. Tests were carried out in the frequency range of 0-1600 Hz. The best sample is a sample with a 25% void ratio that could absorb sound over a long frequency range of 432-1600 Hz even though it only reaches class B. While the highest value of absorption coefficients was the sample with a void ratio of 20% which reach a value of 0.99997. The highest stiffness was achieved by 5% void concrete with a value of k= 5.8×10⁶.

Abstract: The development of structural materials used in the building process is certainly subject to the local and temporal potentials and to how the extent to which the human thought made in the scientific and industrial field. Where the constructional methods that depend on pottery, bricks were and still essentially adopted. The advanced human thought attempted making more efforts to find constructional materials of certain specifications. Porous concrete Light Weight Concrete (LWC) is considered a good alternative constructional material in addition to its light weight and good thermal isolation. It is currently used in Iraq as concrete block to form breakers only. This research includes essential information about LWC and developing it through the adding paraffin wax to generate a material of high moisture isolation, low absorption rate and high bearing for compressive forces especially after overflowing it with wax.

Abstract: The high percentage of porosity in porous concrete pavement tends to decrease its strength. In concrete industry, nano silica is one of the most popular materials that will improve the properties of cementitious materials. This paper, prepared to review the effect of nano silica in cement paste and mortar related to porous concrete pavement. It was found that, by incorporating nano silica with the right composition in cement paste and mortar, it will improve their mechanical properties. By incorporating nano silica in the mixture, it can be predicted that the strengthening effect of nano silica would be further enhanced in porous concrete because the nano silica improve not only the cement paste, but also the interface between paste and aggregate.

Abstract: Subject of the article is development of reinforced sound-deadening panel of new generation for protection of the environment against noise coming from operation on linear transport buildings. These reinforced sound-deadening panels are made from cavern concrete, reinforced with concrete steel reinforcement protected with special anti-corrosion coating. Prototype of the panel was tested according to valid standards from the aspect of acoustic parameters, material characteristics of used concrete and mechanical parameters of the panel.

Abstract: In this article the single-layer homogeneous enclosure structure are considered. In this work calculation of vapor permeability of walls from gas-concrete blocks is made. The calculation of resistance to vapor permeability for rough walls and for walls with an external plaster covering is made. Calculation is executed in the context of St. Petersburg climatic conditions for external walls of residential buildings.

Abstract: The paper study the deformation characteristics of the Prefabricated bamboo reinforced porous concrete slab through points with four points focused beam loading method. The results show that flexural behavior of prefab slab can be improved by adding bamboo reinforcement. Along with the increase of bamboo reinforcement ratio, deflection of prefab board will gradually reduce. Through the loading deflection curve, we can discover that the bamboo reinforced prefab slab with the linear elastic state, and the slab can withstand a certain load after cracking. Bamboo reinforced with strengthening and toughening effect for porous concrete, prefabricated bamboo reinforced porous concrete plate can be used better in slope protection engineering.

Abstract: Porous concrete also be called macropterous concrete or porous lean concrete.As a new base material,it is a lean concrete between cement stabilized macadam and ordinary concrete.Based on Luoyang beltway project,this paper describes the composition design of porous concrete,and discusses the combination of construction machinery,technological process,QCS(quality control specification) and test detection of porous concrete permeable base.Also we do research on many technological parameters such as mixing,paving,molding,maintenance in the construction of porous concrete permeable base.This provides a reference on construction technology and its application.

Abstract: Moisture damage is one of the main forms of early failure in the pavement. Water can be released from the road structure by setting porous concrete permeable base. The common construction technology for porous concrete is traditional vibration compaction, which is helpful for the strength formation of the base. However, it is unhelpful for the stability and smoothness of the base during the construction. In this study, compaction-free porous concrete (CPC) permeable base was proposed, which can not only satisfies both porosity and the structural strength, but also guarantees the stability and the smoothness of the base during construction. The performance of normal porous concrete (NPC) and CPC, such as strength, drainage capacity, shrinkage and frost resistance, were studied in the paper. The laboratory tests show that all of them have good performance. In addition, the field evaluations, such as strength, drainage capacity, deflection, smoothness of the base, were tested. The results show that both of NPC and CPC have good drainage capacity, and the strength of NPC is higher than CPC, but the smoothness of NPC is weaker than CPC.

Abstract: Porous concrete is one of the innovative and promising concrete products, which is featured with a relatively high water permeability rate. Compared with conventional concrete products, due to the lack of fine aggregates in the mix design of porous concrete, the void spaces between the coarse aggregates remains unfilled and causes a large amount of porosity in the hardened concrete mass. On the other hand, the strength of porous concrete is usually lower than that of the conventional concrete products due to the lack of fine aggregates. For the purpose of achieving a relatively high strength of porous concrete while maintaining a good permeability of pavements, the mix design of porous concrete is modeled as a Markov Chain Monte Carlo (MCMC) system and a Gibbs Sampling method based approach is developed to approximate the optimal mix design. The simulation results show that, by using the proposed approach, the system converges to the optimal solution quickly and the derived optimal mix design achieves the tradeoff between the compressive strength and the permeability rate.

Abstract: In this paper, through the test to determine the polystyrene granule as aggregate, the cement foaming slurry as cementitious material, with various additives for the performance adjustment material, optimum matching of polystyrene particles made of lightweight aggregate cellular concrete heat preservation material ratio, was the influence of raw materials on the performance and the thermal insulation of building production technology product form and key.