CS244851B1 - A method of preparing concrete mix from desert sand - Google Patents

Abstract

The method of preparing a concrete mixture from desert sand solves the problem of replacing conventional aggregate with material from local sources in desert conditions. The goal was achieved by replacing the aggregate partly with foamed material and partly with desert sand.

Description

The invention relates to a process for the preparation of a concrete mixture of desert sand by suitable treatment of aggregates.

In the construction of buildings in the desert, all building material had to be transported to the construction site so far, because desert sand with known methods could not be used for processing concrete mixture for the production of building materials.

In particular, its very fine grain was an insurmountable obstacle. At the connection of such fine sand, the consumption of binder was so high that it was more convenient to transport the necessary aggregates to long distances. For example, for the construction of buildings in the desert in North Africa, high-quality aggregates for concrete mixes were imported by ships from Europe and then into the desert by car.

Aggregates from nearby quarries were also provided. However, this aggregate was not of good quality because of the lack of water in the quarries it was not possible to wash it, so it contained a large proportion of fine parts, which again required increased binder consumption. In both cases, transportation in the desert has always been very costly and, in desert conditions, a limiting link for the construction of buildings.

These drawbacks are solved by the invention of a process for the preparation of a concrete mix from desert sand, the principle being that per 1 m ^{3 of the} concrete mixture is used in parts by weight of loose Portland cement 30 - 21%, mixed in 16 - 11%. water, to which 5.6 to 0.3% of the foamed material, for example polystyrene, is added, followed by 48.4 to 67.7% of desert sand.

According to the method of preparation of a concrete mixture from desert sand according to the invention, a concrete mixture -3-1 -1 having a density of 700 to 1,750 kg.with a thermal conductivity of 0.3 to 0.6 W m K with a strength of 3 to 15 MPa cm is obtained. It is non-flammable with good thermal insulating properties and can be used for the production of building components such as blocks, panels, blocks, slabs, etc.

The main advantage of the method according to the invention is that a substantial proportion of the concrete aggregate mixture is replaced by desert sand. Practically two-thirds of the weight in the concrete mix is replaced by a material from an immediate local source in the desert, and only a third of the necessary material, ie cement, water and non-foamed polystyrene, must be transported to the construction site.

This represents high savings in transport costs. Even more important, however, is the increase in the technical use of means of transport in the desert, which will result in an increase in the volume of construction work and an accelerated pace of construction. The construction of the building achieves high savings on insulating materials.

The process of preparing the desert sand concrete mix according to the invention requires no new equipment. The well-known concrete mixing plants commonly used are quite suitable. It is only necessary to add the equipment for foaming polystyrene according to known procedures.

The batch of water is first introduced into the mixing vessel, then the bulk cement is added, followed by the first batch of water, then the bulk cement is added, followed by the foamed polystyrene. The mixture is thoroughly mixed so that the foamed grains of polystyrene are perfectly covered by the cement particles and the desert sand is then metered according to the prescribed quality of the concrete mixture.

After perfect mixing, the concrete mixture is swung out of the mixing vessel and processed by known methods.

Example 1

O

For the preparation of 1 m of concrete mixture, 190 kg of loose Portland cement is used,

100 kg of water, 15 kg of foamed polystyrene and 495 kg of desert sand. A concrete mixture of approximately 800 kg is obtained, which after drying the excess water is reduced to a weight of concrete products of approximately 760 kg.

Example 2

For the preparation of 1 m ^{3 of} concrete mixture, 340 kg of loose Portland cement is used,

180 kg of water, 6 kg of foamed polystyrene and 1,074 kg of desert sand. A concrete mixture of about 1,600 kg is obtained, which after drying of the excess water is reduced to a weight of about 1,540 kg of concrete products.

The concrete mixture obtained can be used according to Example 1 for the production of structural components having a strength of about 5 MPa cm @ ³ , and according to Example 2 for the production of structural components having a strength of about 11 MPa cm @ ³ . The components have an average thermal conductivity of about 0.49 W / mK

The concrete mixture produced in this way is suitable for the production of blocks and blocks that can be used for load-bearing masonry, thermal insulating filling masonry and partition walls. The masonry can be surface-treated in any known manner, for example by plastering, tiling, spraying and the like. The finished products have satisfactory strength, are substantially lighter, have good thermal and acoustic insulation properties and are non-flammable.

Preparation of concrete mix from desert sands is designed to create a technical prerequisite for the construction of buildings in desert areas.

Claims (1)

Method for preparing a desert sand concrete mixture characterized in that 30 to 21% by weight of Portland cement, mixed in 16 to 11% of water, into which 5.6 to 0.3% of the foamed foam is added, is used per 1 m ^{3 of} concrete mixture. 48.4 to 67.7% of desert sand.