Aug 07 2018

Specified Water

Properties of lung betonUdoboukladyvaemost lightweight concrete mixtures evaluated by the same methods that are used for concrete governmental mixtures of dense aggregates. Selection of the quantity of water at the specified index of workability complicated by the fact that the latter depends on the nature of the applied porous filler. Fundamentals of the Theory of lightweight concrete, as well as a general method for selecting optimum quantity of water for light concrete mix designed by N. Popov. This method is based on the dependence of strength and yield ratio of lightweight concrete by water flow curve of the strength of water flow has two branches. The left (ascending) shows that the strength of concrete with an increase in water consumption is gradually increasing.

This is due to an increase in the workability of concrete mix and density of concrete. Right (Descending) branch of the curve indicates that after reaching the maximum compaction of the mixture (ie, the minimum coefficient of output) increase in water consumption increases the volume of pores formed by non- cement, water, and a decrease in concrete strength. In the lightweight concrete is clearly seen as a lack of adverse effects, and the excess of water. The most important (along with strength) characteristic of lay Who concrete is bulk density. Depending on the volume weight and destination lightweight concrete is divided into the following groups: heat-insulating with a bulk weight of 500 kg / m 3 or less; constructive tionally – insulating (for building envelope – walls, roofs of buildings) with a weight up to 1400 kg/m3; construction with a weight 1400 – 1800 kg/m3.