crack resistance

STUDY OF FINE-GRAINED FIBER CONCRETE CRACKING RESISTANCE FROM THE POINT OF VIEW OF DESTRUCTION MECHANICS

Fiber reinforced concrete began to appear in the market in the 60s of the last century, and since then the interest in this type of reinforcement has been steadily growing. The article presents the results of studies on the crack resistance of concrete reinforced with polypropylene fibers of various lengths and volume concentrations in fine-grained concrete. Waste from the wet magnetic separation of the Poltava mining and concentration plant was used as an aggregate in the concrete. Polypropylene fibers with the various lengths diameter of 0.2 mm were used for reinforcement.

Laser surface modification of materials

To develop any process of laser technology, you need to solve 3 problems: 1) What are the properties of the interaction of laser radiation with matter must be selected to achieve the goal (resonant – non-resonant, absorption-scattering, photo- or thermal absorption, heating, hardening, melting, softening, evaporation, decomposition, coagulation, etc.); 2) What type of laser source should be used to achieve this goal (wavelength, operation mode – continuous or pulse-frequency, power, pulse duration, transverse energy distribution in the beam, coherence

MECHANICAL PROPERTIES OF CEMENT CONCRETES INCORPORATING GROUND TIRE RUBBER

This article proves the possibility of replacing aggregates in concrete mixtures with rubber, which is obtained by grinding used car tires. It was found that the replacement of crushed coarse aggregate in the amount of 10 vol.% with ground rubber from used car tires increases the bending strength by 23% The compressive strength does not change significantly.

INVESTIGATION OF ENGINEERED CEMENTITIOUS COMPOSITES PROPERTIES

Concrete is the most widely used building material due to its versatility, durability and availability of raw materials. With the development of the construction industry requirements to concrete, in particular their strength, are increased. Increasing of the physical and mechanical properties and crack resistance of cementitious composites during the operation of buildings and structures is an actual problem in engineering practice. A special class of fiber reinforced materials – engineered cementitious composites (ECC) has been developed for this purpose.

Експериментально-статистичне моделювання тріщиностійкості бетонів, армованих поліпропіленовою фіброю. Частина ІІ

One of prospective construction materials, which allow compensating such concrete lack as low tensile strength and high destruction fragility, is continuously reinforced concrete – fibrous concrete.

Вплив захисного шару бетону на тріщиностійкість, деформативність та несучу здатність залізобетонних балок, армованих сталевим просічно-витяжним листом

Concrete, smooth and fluted corrugated bar reinforcement, flat and fluted sheet steel, shaped roof deck are used, as a rule, for prefabricating reinforced concrete beam structures with external sheet (ribbon) reinforcing. However the scientists passed by the rather interesting type of sheet reinforcement called cut-stretching sheet. Due to its particular geometrical shape of lateral surface and strength features cut-stretching sheet can also be used as external reinforcement in reinforced concrete structures.