Cohesion Test of a Single Impregnated Ar-Glass Roving in High-Performance Concrete

Abstract

The development of light and very thin concrete building structures and demand for extremely thin elements in design are inter alia reasons for the development of composite materials as non-traditional reinforcement. Composite materials are currently used as reinforcement mostly in the form of fiber reinforced polymer bars similar to traditional steel reinforcement bars, but the last decade sees also rise in the use of technical textiles. This article is focused on the interaction between impregnated textile reinforcement and high-performance concrete matrix and its easy determination using originally modified pullout test. The second aim of this article is improvement of interaction conditions between reinforcement and cementitious matrix using fine-grained silica sand applied on the surface of the composite reinforcement similarly to the traditional fiber reinforced polymer reinforcement with commonly used diameters. To investigate an effect of this modification a bending test was performed on small thin concrete slabs with different amounts of reinforcement.

Use of Cement Suspension as an Alternative Matrix Material for Textile-Reinforced Concrete

“…It is evident from the mechanical test results ( Figure 14 ) that the B series samples showed a similar trend of bending capacity increase, mainly in the initial phases of crack development, as has been shown in reference samples Epoxy 1. However, due to an alternative material used in this study, the results of this solution deviate from that of conventional TRC with an epoxy resin matrix [ 44 , 45 , 46 ] and a comparison of results is therefore problematic. The best-aperforming combinations (sample series A and B) will be further investigated by mechanical tests focusing on a detailed description of cement matrix behavior, for example the so-called pullout test based on simple co-interaction of one cement-saturated carbon roving with concrete.…”

Reinforced L-Shaped Frame Made of Textile-Reinforced Concrete

“…The experiments regarding the carbon textile impregnated with epoxy resin were performed in two variants to evaluate the effects on cohesion. The first variant was with the smooth untreated surface of the impregnated rovings, while the second was with surface treatment using a fine-grained silica sand [ 17 , 21 ].…”

“…The tensile strength of carbon reinforcement was tested using LabTest 4.100SP1 testing machine with a constant increment of displacement of 1.2 mm/min on rovings impregnated with epoxy resin. Impregnation of rovings ensured proper interaction of all fibers [ 17 ]. The ultimate tensile strength was dependent on the quality of resin impregnation, as improperly coated fibers broke prematurely, and the tensile strength decreased.…”

“…The most important parameter was the value of the force when the reinforcement started slipping. Based on the results, a diagram was created that could be used to set the bonding properties in the numerical analysis [ 17 ]. Due to almost immediate slipping in the case of smooth-surfaced reinforcement, only reinforcement with a modified surface was chosen for further use.…”

“…The presented experiments include only impregnated carbon textile reinforcement. Carbon rovings were impregnated with epoxy resin to ensure the homogenization of individual fibers [ 17 ]. To validate and calibrate the model inputs, a sub-model of a four-point bending test of a thin TRC plate was created in the Atena Engineering software supported by mechanical experiments.…”