A research of fibrous gypsum modified with a complex additive has been undertaken. The objective of the research was to identify influence and dosage of complex additive components upon fibrous gypsum water absorption. To fulfil the work there were used gypsum plaster and a modifying complex additive which consisted of the following components: polypropylene fibre, fine-dispersed inert aggregate, super-plasticizer and redispersing polymerous powder. To undertake the research designing an experiment took place and the central composition plan was implemented. The obtained research result made it possible to calculate and analyze descriptive statistics. Positive influence of the researched factors on water absorption decrease was revealed. It was established, that consumption of fine-dispersed inert aggregate and, super-plasticizer promote decrease of fibrous gypsum water absorption. Analysis and processing of the research data allowed obtain a mathematical model of influence of complex additive components consumption on fibrous gypsum water absorption and reveal a fibrous gypsum composition with the minimal water absorption. The obtained model allowed forecast a composition with the minimal water absorption.

Keywords: fibrous gypsum, water absorption, complex additive, modified, central composition plan, model, additive efficiency.

The article discusses the various proportions of the components of the cement-sand mixture for the production of bricks for the construction of private houses. Particular attention is paid to the values ​​of the draft of the cone, as one of the indicators of the mixture. Tables are given with a description of the different composition of the mixture for each component. The results of an experiment to study the effect of different ratios of components are presented. The equipment for manual and automatic molding and creation of finished products from the resulting mixture is illustrated. A conclusion is given on the possibility of using a specific mixture in the production of bricks.

Keywords: brick, cement, sand, water, cement-sand mixture, cement mortar, water-cement ratio, composition selection, construction, production