К ВОПРОСУ ВЫБОРА ОПТИМАЛЬНОГО ВОДОЦЕМЕНТНОГО ОТНОШЕНИЯ ПРИ ПРОИЗВОДСТВЕ ТЕПЛОИЗОЛЯЦИОННОГО ПЕНОБЕТОНА

Abstract

The article considers the influence of the water-cement ratio on the formation of the structure of thermally insulating foam concrete, having the D300 average density grade. The basis for the analysis is the contradiction between the experimentally obtained direct dependence of the strength of foam concrete on the water-cement ratio and the practice of improving the structure of the material due to water reduction. The computation of the optimal amount of water in the foam concrete mixture based on the method of absolute volumes is presented. The calculation includes a formula for determining the volume of the interpore space depending on the thickness of the interpore partition, the cell diameter and the type of packing. The actual indicators collected during the experiment confirm the results of the calculations. The influence of the amount of water in the foam concrete mixture on the quality of the foam concrete is evaluated by the compressive strength and the macrostructure character of the material. The strength is determined by the destructive method. The structure is studied using an optical microscope in combination with image processing software. The greatest strength is possessed by a material with a partition thickness exceeding the maximum size of the cement grain, provided that the volume of the interpore space and the sum of the absolute volumes of the components of the foam concrete mixture are equal. A structure with closed pores and dense interpore partitions is observed in foam concrete on a protein foam former with a water-cement ratio, taking into account water in the foam, equal to 0.7.