Cellular Concrete Products Research Articles

Structural Modeling of Pneumatic Actuators of the String Tension at the Installation for Cutting the Raw Cellular Concrete

In the manufacture of cellular concrete products a string cutting of the raw material before autoclaving is widely used. The quality of cutting which represents the interaction of the string with a moving mass of the raw material is largely determined by the dynamics of the string deflection size Δх especially at the stage of its insertion and withdrawal from the material. So it is very relevant to stabilize Δх through the system of the automatic string tension. The structure of the proposed control system by the pneumatic cylinder, which is used as the power actuating tensioning device, is presented in this paper. The system contains two circuits. The inner circuit is closed by the pressure magnitude in the pneumatic cylinder, while the outer one by the axial force of the string measured with the strain sensor, which is structurally located between the pneumatic cylinder and the string. Itis shown that the use of such system increases the service life of the string and reduces deficiencies formed at the string withdrawal from the raw material.

The influence of cellular concrete surface modification on its physical and mechanical properties

Interaction of polyorganosiloxanes of different spatial structures with polymethylmethacrylate and epoxide resin in different ratios was investigated, namely double and triple systems were considered in the paper. The obtained systems were used in modifying the cellular concrete surface and identifying the main physical and mechanical properties such as surface adsorption, impregnation depth, water absorption, ultimate bending strength.Modifying the surface of cellular concrete was conducted to improve its performance properties since at the large number of open capillary pores during operation in outdoor conditions, products lose their basic feature − heat insulating. Also, modified products have a 5 times higher ultimate bending strength.As a result of studies, it was found that impregnations, based on silicone varnish KO-075 were the most effective modifying compositions. They united 2 principles at once: surface hydrophobization with its simultaneous strengthening. The obtained data are of great interest for both researchers and cellular concrete products manufacturers. Modifiedcellular concrete products can be used as supporting structures in low-rise construction that in turn will lead to saving energy and labor costs.

FOAM CONCRETE ON THE BASIS FILLERS FROM RECYCLED MATERIALS

The paper is devoted to the actual problem recycling crushing screenings brick battle and workmanship bricks using it as a fine aggregate in cellular foam concrete products. The paper presents the analysis of the environmental situation of the region and the results of a study of waste crushing brick fight to improve the utilization of the product technology in cellular-concrete products. A comparative study of traditional cellular gas concretes and foam concretes and concretes based on recycled sand.

Utilization of crushed clay brick in cellular concrete production

The main objective of this research program is to study the effect of using crushed clay brick as an alternative aggregate in aerated concrete. Two series of mixtures were designed to investigate the physico-mechanical properties and micro-structural analysis of autoclave aerated concrete and foamed concrete, respectively. In each series, natural sand was replaced with crushed clay brick aggregate. In both series results showed a significant reduction in unit weight, thermal conductivity and sound attenuation coefficient while porosity has increased. Improvement on compressive strength of autoclave aerated concrete was observed at a percentage of 25% and 50% replacement, while in foamed concrete compressive strength gradually decreased by increasing crushed clay brick aggregate content. A comparatively uniform distribution of pore in case of foamed concrete with natural sand was observed by scanning electron microscope, while the pores were connected mostly and irregularly for mixes containing a percentage higher than 25% clay brick aggregate.

Properties of the wall structures made of autoclaved cellular concrete products on the polyurethane foam adhesive

Properties of the wall structures made of autoclaved cellular concrete products on the polyurethane foam adhesive

The Use of Anthracite Fly Ash for the Production of Autoclaved Aerated Concrete

Burning high-quality anthracite coal produces ash with a high content of unburned residues, which in many cases permanently exceeds 20%. These ashes usually contain high levels of amorphous phase providing the pozzolanic activity, this making them particularly useful if potentially applied in the construction industry. Such potential of effective treatment necessitates reducing the content of unburned residues, the best level here being less than 4% w/w. This paper deals with the results of testing heat treatment of fly ashes particularly using the resources of eastern Slovakia. Tests have shown that tested process of heat treatment can safely reduce the content of unburned residues in fly ash whilst maintaining high levels of the glass phase. Raw materials thus modified meet the requirements for the use in cellular concrete production technology with beneficial use of exothermic reaction heat from fly ash treatment in pre-heating the autoclaves.

Replacing Al powder with Al slag or recycled foil in cellular concrete

Before aluminum wastes are used in cellular concrete, it is very important to exactly determine the amount of aluminum in slag and to know the aluminum’s chemical reactivity. The cellular concrete composition must be adjusted according to variations in the composition of the aluminum waste. As a result, a process control system designed to handle such variations would be helpful in controlling the quality of the final cellular concrete products. With regard to the use of waste aluminum foil, further experiments involving aluminum powder size control and additives are suggested.

Siliceous cellular concrete made from flotation tailings

Based on the results of large-scale industrial experiments, the value of utilizing flotation tailings for the production of cellular concrete is discussed. The paper is confined to the technical and ecological aspects of the process.

Cellular Concrete—A Promising Building Material

The cost of building materials constitute 65% of the construction. A wide gap exists between the requirement and availability of building materials in the country. In order to meet the gap, among the new and substitute materials introduced by the NBO, one is Cellular Concrete. Substantial savings in the critical materials such as steel and cement with overall economy is achieved in building construction by its use. Two plants one at Madras and the other at Poona have started producing Cellular Concrete products. The properties, the process of manufacture and the economy achieved by the use of cellular concrete in construction is dealt in this article. The production of Cellular Concrete enables utilization of large quantities of fly-ash, a waste material from the thermal power stations.