The article presents the influence of pozzolanic additives and polycarboxylate superplasticizer on the performance of the cementitious matrix of recycled aggregate concrete. The particle size distribution by volume and surface area of fly ash and silica fume is given, and the phase composition and microstructure of cementing paste are investigated.
The effect of natural and synthetic zeolite on the microstructure of cement matrix and mechanical properties of concretes was studied in the article. Results show that the addition of these pozzolanic materials results in the increase both compressive and flexural strength after 28 days of hardening. The concrete incorporating 10 mass.% of synthetic zeolite Na-P1 characterizes the highest compressive and flexural strength that reaches 53.5 and 7.8 MPa and exceeds the strength of reference concrete by 18 and 24%, respectively.
The exponential expansion in concrete use has put the environment under immense pressure to supply cement, aggregates, and water. Natural resource consumption impacts the environment and undermines the concrete industry. A swift shift towards sustainable concrete is required considering the emergency triggered by human activity on the climate. Glass concrete (GC) has sparked the curiosity of the construction industry owing to its environmentally friendly approach.
The sustainability of the concrete industry is in jeopardy due to the use of natural resources which impacts the environment. A swift shift towards sustainable thinking is required considering the emergency triggered by human activity on the climate. Glass concrete (GC) has sparked curiosity of the construction industry owing to its environmentally friendly approach.
Exposure to elevated temperatures has detrimental effects on the properties of concretes based on the Portland cement, leading to irreversible changes, up to total failure. One of solutions to improve resistance of structures after exposure to high temperatures may be the use of cement-based materials modified at the nanoscale.
In many countries (Japan, USA, China, Poland, etc.) the studies of the influence of laser radiation on the surface of various building materials are being carried out for a long time, including the military purposes. Most attention has been paid to the interaction of laser radiation with the surface of metals.
The paper presents results of work on 3-D the surface scanning system using ERT method. The construction of automatic laboratory system for imaging of the internal structure and heterogeneity of concrete structures by ERT method, using a multi-electrode surface scanner of electrical conductivity of concrete objects will be used to model tests and actual concrete structures by multi-point and non-contact method for measuring the electrical conductivity of concrete structures, in particular.
In this article describes theoretical and experimental research of contact seams in the repair or strengthening concrete elements using concrete, sprayed-concrete anchors and substrate binding.
This paper shows the possibility of increasing the fire resistance of the normalized tunnel concrete structures up to 120 min through the use of thin-film intumescent geocement base coatings in the conditions of temperature carbohydrate fire. It is established that the developed structure fire coating thickness of 6 mm prevents heating of the surface layer of concrete under the cover to limit state – 380 °C.
The effects of surface treatment of concrete filled silicon organic components in the adhesive strength and the integrity of the protective layer are investigated.