MATEC Web of Conferences, open access proceedings in Materials science, Engineering and Chemistry

The article presents experimental research on the development of the optimal composition of cement-fibrous composite material for the manufacture of autoclaved fiber-cement boards with high physical, mechanical and economic parameters. The effect of the cement-sand ratio of the matrix, the specific surface area of the sand and the cellulosic fibers content on the physical and technical properties of the material is shown. It is established that the optimum cement-sand ratio of the matrix associated with a specific surface area of quartz sand 310 m²/kg is 1:2. The optimal content of cellulosic fibers according to the criterion of increasing the strength is 5-7.5%.

Gypsum and gypsum-cement-pozzolanic composites are of significant interest as materials and products for building decoration. The current tendency to reduce the consumption of gypsum-based materials and products in the context of growth and development of the finishing materials market depends on the decrease in their competitiveness compared to peers. This leads to significant interest in improving the quality of products based on gypsum and gypsum-cement-pozzolanic binder. Dispersed reinforcement is one of the ways of improving performance characteristics. The role of the type of reinforcing fibers in the formation of the gypsum-cement-pozzolanic composites structure and properties is studied in article. The influence relations of the cellulose fibers content with varying grinding degrees on the relative flexural and compressive strength of a gypsum-cement-pozzolanic matrix are obtained. It was found that the optimal content of cellulose fibers in the modified gypsum-cement-pozzolanic matrix is 0.5-1% by weight of the binder, the best indicators of flexural and compressive strength are achieved by grinding cellulose fibers to 30°SR. Using scanning electron microscopy, it was found that the microstructure of a disperse-reinforced gypsum-cementpozzolanic matrix is characterized by a uniform cellulose fibers distribution, the predominance of directionally frame reinforcement with a fibers linear orientation in the sheet plane. In this way the right choice of the type, crushing degree and cellulose fibers content can improve the quality and expand the application area of the produced gypsum-cementpozzolanic composites.

В работе изучены особенности применения пластифицирующих добавок на основе эфира поликарбоксилата в технологии аддитивного строительного производства (3D-печати). Послойную экструзию осуществляли на 3D-принтере «АМТ S-6044». Исследованы нормальная густота и сроки схватывания цементного теста, средняя плотность, пластическая прочность и формоусточивость бетонной смеси, пределы прочности бетона на сжатие и при изгибе. Показано, что пластифицирующие добавки на основе эфиров поликарбоксилатов в рассмотренных концентрациях являются эффективными модификаторами реотехнологических и физико-механических свойств цементных бетонных смесей, применяемых в технологии 3D-печати. Наибольшее увеличение прочности на сжатие и при изгибе при введении исследуемых поликарбокисилатных пластификаторов наблюдается на ПЦ ЦЕМ I 42,5Н: введение 0,5% «MasterGlenium 430» приводит к увеличению прочности при сжатии и изгибе на 49,3% и 31,6%; при введении «MasterGlenium 115» - на 21,6% и 35%; при введении «MasterGlenium 591» - на 49,8% и 41,7% соответственно. Интерес для дальнейших исследований представляет разработка комплексных органо-минеральных добавок полифукнкционального действия на основе поликарбоксилатых ПД для бетонов, формуемых методом аддитивного производства...

The paper shows the effectiveness of the use of a polyfunctional complex modifier for a gypsum-cement-pozzolanic binder (GCPB), which allows reducing the water requirement of the mixture by 35%, increasing the flexural strength of gypsum-cement-pozzolanic composites (GPPC) by 28%, and 25% for compression. The results of experimental studies of the effect of polypropylene fibers on the basic physicomechanical properties of a central processing center are presented. The performed studies have shown high efficiency of polypropylene fibers of the type VSM-II-6 for dispersed reinforcement of the central industrial park. The maximum increases in the values of the flexural strength (by 41.2%) and compression (by 20%) are achieved with their volume content in the amount of 1%. It should be noted that the introduction of the studied fibers with a length of more than 6 mm did not lead to the expected result, which is due to the formation of a heterogeneous structure of the GPPC

The article presents the results of experimental research of the influence of organosilicone compounds on porosity parameters, contact angle of fiber cement panels based on cellulosic fiber in superficial expansion and volumetric methods of hydrophobization.