compressive strength

Production of foam concrete products and monolithic concreting from them requires foaming agents that have the properties of the obtained foam with a sufficient value of its criteria (multiplicity of foaming, stability of foam for a certain period of time); its compatibility with Portland cement and its hydration products; with hydrated lime, etc. Insufficient properties of the foam can be compensated by the introduction of corrective and stabilizing additives.

In conditions of intensive increasing of urbanized impervious areas, stormwater management became especially relevant. To solve this problem, a number of methods have been developed and investigated, which are based on the retention, detention or filtration of stormwater runoff. Stormwater management by the pervious pavements is an effective method to control surface runoff; it is widely used in foreign practice, allowing to reduce the runoff volume, provides its preliminary treatment, improves the safety on the roads.

One of the actual problems of the further sustainable development of construction industry is solution of energy and resource saving problems during production and reduction of harmful emissions. Building materials based on gypsum raw compared to cement materials of analogical purpose are characterized by low energy consumption, as well as better ecological indicators. However, gypsum materials without modifying additives have low strength and water resistance which limits their application to the area of internal processing of rooms with a relative humidity of up to 60 %.

In the work was studies of pozzolanic activity complex additives with waste glass powder and nano-silica. The estimate option value and weight ratio of waste glass powder and nano-silica in cement mortars for destination of improving his property.

In this contribution is presented overview of aggregate from recycled concrete and steel making slag treatment in civil engineering industry. The goal of experiments is utilization of these wastes as the partial or complete replacement of natural aggregates fraction 4-8 and 8-16 mm in concrete. Partial replacement was carried out from 20 to 80 %.

By using hydroxypropyl derivatives of urea esterified with boric acid as polyol components and 4,4’-diphenylmethane diisocyanate the rigid polyurethane foams have been obtained. The influence of boron and nitrogen atoms on the properties of foams, inter alia compressive strength and flammability, has been discussed. The presence of borate groups enhances the compressive strength of polyurethane foams meaningfully. However, the flammability of foams is determined by the participation of carbamide groups mainly.

The usage of fine grinded silicate glass as an active additive to Portland cement has been considered in order to substitute neat cement in the cement composition, just as it is in EN 197-1 European standard by the example of active mineral additives of natural and artificial origin.