The strength of compressed structures with CFRP materials reinforcement when exceeding the cross-section size

Abstract

Abstract. The increase of high-rise construction volume or «High-Rise Construction» requires the use of high-strength concrete and that leads to the reduction in section size of structures and to the decrease in material consumption. First of all, it refers to the compressed elements for which, when the transverse dimensions are reduced, their flexibility and deformation increase but the load bearing capacity decreases. Growth in construction also leads to the increase of repair and restoration works or to the strengthening of structures. The most effective method of their strengthening in buildings of «High-Rise Construction» is the use of composite materials which reduces the weight of reinforcement elements and labour costs on execution of works. In this article the results of experimental research on strength and deformation of short compressed reinforced concrete structures, reinforced with external carbon fiber reinforcement, are presented. Their flexibility is λh=10, and the crosssection dimensions ratio b/h is 2, that is 1,5 times more, than recommended by standards in Russia. The following research was being done for three kinds of strained and deformed conditions with different variants of composite reinforcement. The results of the experiment proved the real efficiency of composite reinforcement of the compressed elements with sides ratio equal to 2, increasing the bearing capacity of pillars till 1,5 times. These results can be used for designing the buildings of different number of storeys.

The deformability of short pillars in various loading options and external composite reinforcement

“…It is under these loads that all types of stressed-deformed state of compressed elements are covered. This article is a continuation of the already mentioned article [17], where the strength indicators of short pillars for various varied data are analyzed in detail.…”

“…It is carried out in three directions. The bent elements reinforcement can be along the normal (1st) and oblique sections (2nd) directions [11][12][13]. The third direction is the reinforcement of compressed elements of different flexibility [14]; type of stressed-deformed state [15,16] and options for transverse or longitudinal reinforcement [17].…”

The beams with composite reinforcement inclined sections’ finite element modeling operation results comparison with the results of the laboratory samples’ tests

“…As part of a large-scale study of the work of reinforced concrete structures reinforced with composite materials, at the Department of Reinforced Concrete and Stone Structures, DSTU, the operation issues of reinforced concrete structures reinforced with round glass and carbon fiber reinforcement [1][2][3][4], the sections strength of reinforced concrete beams normal to the longitudinal axis of the element, reinforced external composite reinforcement [5], compressed reinforced concrete elements reinforced with composite materials at different eccentricities of load application [6][7][8][9]. Also, a study on the sections of reinforced concrete beams that are inclined to the longitudinal axis of the element, reinforced with external composite clamps in the presence and absence of initial inclined cracks was carried out [10][11][12][13][14].…”

Initial crack effect on the strength of oblique cross sections of reinforced concrete beams strengthened with carbon fiber

“…The strength of normal to longitudinal axis of the section structures of flexible concrete elements, with normal and excess cross-sectional area of composite materials, is studied. Experimental studies of the compressed RC elements reinforced with composite materials with various eccentricities of load application are completed [1][2][3][4][5][6]. Currently, the strength of oblique cross sections of RC beams with initial diagonal cracks strengthened through the external composite transverse reinforcement is investigated.…”