Строительство и архитектура /4. Современные строительные материалы

O. Shynkevych , D. Linnik, S. Zakabluk

Odessa State Academy of Civil Engineering and Architecture

Selection and optimization fractional composition of organic filler

for arbolite

To date, the so-called "warm houses" and "ecohouse" are gaining wide popularity. One of the materials for the construction of this type of house is the arbolite. Arbolite or arbolit concrete - a building material, a kind of light concrete. It is made by mixing organic aggregates (crushed woodworking waste, cane, hemp, etc.), binding (usually Portland cement) and water. The crushed organic filler gives the arbolite unique sound and heat insulation properties. From the arbolite, wall and heat-insulating blocks, panels, slabs for the erection of low-rise residential, public, industrial and agricultural buildings are manufactured. Today, this topic is again becoming more urgent, because allows to solve the issues of resource and energy saving, convenience and speed of erection of buildings, to reduce costs for housing construction.

Strength of arbolitobeton is determined by many factors: the type of binder and its main properties, the granulometric composition of the organic aggregate, the ratio of binder and aggregate. Analysis of the state of the issue in the world showed that cement is mainly used as the main binder for arbolitic concrete [1]. In this study we used a gypsum-cement pozzolanic binder.

To solve the problem of selecting and optimizing the composition of the arbolitic concrete, an experiment was conducted to assess the effect of the fractional composition of the organic aggregate on the properties of the arbolit concrete. An experiment to optimize the fractional composition of the organic aggregate is based on the simplex-lattice Sheffe plan for mixtures. Calculation of ES models, visualization of the graphic part is performed in the program STATISTICA. In the experiment, three independent factors were varied: a large fraction of organic aggregate of size X = (10-20) mm, an average fraction of organic aggregate of Y = (5-10) mm in size, a fine fraction of an organic aggregate of Z = (2.5-5) mm in size . Fractions of organic aggregate more than 20 mm and less than 2.5 mm were not analyzed due to their insignificant normalized content in the aggregate [2]. Evaluation of the fractional composition of the organic aggregate was determined by the indices of partial residues on the sieves, in accordance with the standard (DSTU B V.2.7-271: 2011 "Arbolite and articles thereof, general specifications").

As a result of the experiment, three-factor mixed ES models describing the change in compressive strength and density under the influence of the fractional composition of the polymer were obtained.

A quantitative assessment of the effect of each factor (organic filler fraction) on the corresponding response value (compressive strength, density) was performed using ES models. The evaluation of the effect of each factor (organic filler fraction) on the corresponding value of the properties (compressive strength, density) was performed using the graphs shown in Fig. 1-2.

Analysis of the graphs shows that when the content of the coarse fraction (size ≥ 10mm) in an amount of 50% to 100% and the content of the middle fraction (size ≥5mm) in an amount from 0% to 50%, a significant reduction in density is achieved - up to 285 kg / m3 . Influence of fine fraction (size ≥2.5 mm) on strength is insignificant.

Optimization of the composition of arbolit concrete in terms of strength and average density, taking into account the composition of the composite gypsum binder, the fractional composition of the organic aggregate and the ratio of the components in the "binder-organic filler" system. Optimal compositions provide a strength class of B0.35 and B0.5 with a density of 300-312 kg / m3, which is below the normalized density values of 400-450 kg / m3 for these strength classes for arbolitic concrete according to DSTU B B.2.7-271: 2011, below normalized density values of 400-450 kg / m3 for these strength classes for arbolitic concrete in accordance with DSTU B B.2.7-271: 2011.

Fig.1. Influence of the fractional composition of the organic aggregate on the compressive strength of the arbolitic concrete.

Fig.2. Influence of the fractional composition of the organic aggregate density of the arbolitic concrete.

References:

1. Казимагомедов И. Э. Стеновые изделия из арболита на основе костры льна / И. Э. Казимагомедов, А. В. Лобанова // Комунальне господарство міст. Сер. : Технічні науки та архітектури., - 2015, - Вип. 124 - С. 18-20.

2. Оптимизация составов сухих строительных смесей на основе экспериментально-статистических моделей./ Шинкевич Е.С., Тымняк А.Б., Линник Д.С., Тертичный А.А. // Зборник ВАК "Будівельні матеріали, вироби та санітарна техніка". – Київ: товариство "Знання" України, 2013. – Вип. 48.– С. 179-183.