Mechanical Properties Of Rubberized Concrete Research Articles

Experimental Study on Comparison about the Modifiers of Rubber Cement Concrete

5-8 mesh rubber granules was mixed with an equal volume instead of fine aggregate, and the content of rubber was 5%, 10%, 15% and 20%. Compared with the influence of silane coupling agent, latex and silica fume to the mechanical properties of rubber concrete, it studied the mechanism of rubber-modified to the rubber concrete. The test results proved that the silane coupling agent, latex, and silica fume could improve the compressive strength, splitting and flexural strength. Latex could significantly improve the bond strength of cement-based materials and the integrity of the concrete. Coupling agent made rubber bond with cement-based materials to form a stable connection, and silica fume filled the pore in concrete, so it optimized the gradation. Latex was the best, silane coupling agents was second, and silica fume was the last about the improved effect of three kinds of modifiers.

Flexural Characteristic of Rubberized Hybrid Concrete Reinforced With Steel and Synthetic Fibers

Abstract To enhance the low strain capacity and brittleness of concrete, several researchers have already reported on the mechanical properties of rubberized concrete, which lead to reduced environmental concerns, direct cost reduction, low unit weight, high toughness, and improved absorption of impact. However, to overcome the drawbacks of low flexural strength and the low stiffness of rubberized concrete and to improve the crack resistance, steel, or synthetic (polypropylene) fibers, or both, were added into the rubberized concrete in this study. Based on the flexural performance test according to ASTM C1018 and ASTM C1609, this study investigates the combination of crumb rubber, steel or synthetic fibers, or both, in zero-slump concrete mixtures used in the dry-cast production method for concrete pipes. A series of concrete mixes were examined with the variation of the fiber volume fraction (Vf) (steel: 0.17 % and 0.33 %/synthetic-polypropylene: 0.17 %, 0.33 %, and 0.52 %), and crumb rubber with different replacement ratios of 3 % to 20 % (by volume) for sand (fine aggregate) in the concrete mixture. Seventeen rubberized mixtures were developed by incorporating different dosages of steel and polypropylene fibers and their combinations. The influence of fiber type, dosages of fibers, and rubber are analyzed on the basis of experimental results. Results indicate that the effect of hybrid reinforcement using both steel and polypropylene fiber in rubberized concrete is considerable in terms of increase in both peak load and toughness. The specimen of hybrid fiber-reinforced rubberized concrete (HYFRC) with 44 lb/yd3 (0.33 %:Vf) of steel fiber, 8 lb/yd3 (0.33 %: Vf) of polypropylene fiber and 3 % of crumb rubber (replacement with fine aggregates) showed higher peak load, modulus of rupture, and toughness than other mixtures. However, excessive replacement of rubber into the specimens had a negative effect on the flexural properties (strength and toughness).

Mechanical properties and constitutive equations of concrete containing a low volume of tire rubber particles

Uniaxial compressive tests were conducted for a low-volume tire rubber concrete (RC) with different rubber volume content levels and particle sizes (five of each). The influence of rubber content and particle size on the mechanical properties of RC was investigated, including axial compressive strength, elastic modulus, peak strain, ultimate strain, appearance of visible cracks and failure pattern of specimens. The mechanical analysis of test results was conducted based on uniaxial compressive stress–strain curves. Uniaxial compressive constitutive models of low-volume rubber concrete were established that included axial compressive strength, peak strain and constitutive parameters a and b. There was obvious regularity between constitutive parameters a and b, rubber content and rubber particle size. Moreover, the physical meanings of constitutive parameters a and b were given, and the established constitutive models were evaluated by tests. The test results demonstrate that the constitutive models have not only good predicting ability and high accuracy but also nice applicability within the limit of 50kg/m3 rubber content. The constitutive models were then improved by introducing the sand rate reduction factor k to reflect the influence of rubber additives. The improved constitutive models are able to predict the performance of concrete with low amounts of rubber.

Proportion of Tensile Strength and Compressive Strength of the Crumb Rubber Concrete Modified by Silane Coupling Agent

Silane coupling agent built a "molecular bridge" between organic molecules and inorganic molecules, which modified the rubber surface and increased the adhesive ability of rubber particles and cement, so that improved the mechanical properties of rubber concrete. This paper studied on the modification effect of coupling agent on the rubber concrete while the quality of silane coupling agent was 0.5% of that of cementitious material which compared with the mechanical properties of unmodified rubber concrete and the test of concrete under tension and compression ratio and compression ratio were analyzed at the same time.

Experimental Study on the Mechanical Properties of the Crumb Rubber Concrete Modified by Latex

Through modification of the rubber surface, the adhesive ability of rubber particles and cement based materials has increased, thus improving the mechanical properties of rubber concrete. Dosage of styrene butadiene latex was studied under the condition of 5% cement quality, the change regularity of different amount of rubber latex rubber modified concrete compressive, splitting, flexural strength and other mechanical properties. The test results prove that the latex rubber mixing can improve compressive, splitting and flexural strength of concrete.

Hydro-abrasive resistance and mechanical properties of rubberized concrete

Hydro-abrasive resistance and mechanical properties of rubberized concrete

Experimental Research on Properties of Fresh and Hardened Rubberized Concrete

In this study, the use of tire-rubber particles as a replacement for coarse aggregate in concrete is investigated. Rubber has replaced coarse aggregate at content levels of 25, 50, 75, and 100% in concrete by volume. Also, emulsified asphalt (EA) was used to improve the mechanical properties of rubberized concrete. Four different series of concrete mixtures were designed to investigate the effects of the water-cement (w/c) and EA-cement (EA/C) ratios on the properties of rubberized concrete. The slump, air content, dry unit weight, compressive strength, elasticity modulus, and flexural strength have been compared to the corresponding properties of controlled concrete. Consequently, an increase in rubber content leads to a decrease in slump and an increase in air content because of the rough surface of rubber. An increase in rubber content decreases compressive strength, elasticity modulus, and flexural strength because of its lower stiffness and poorer bonding between rubber and the paste matrix. In the case of equal levels of rubber particle content, the addition of EA greatly increases slump. However, the effects of EA on the properties of rubberized concrete, such as air content, strength, and elasticity modulus, are based on the EA/C ratio. A certain level of EA addition can improve the compressive and flexural strength of rubberized concrete. EA addition reduces the elasticity modulus of the concrete. Adding EA is a good way to improve the bonding between rubber particles and cement paste.

Introductory behavior of rubber concrete

This article introduces a new type of concrete, the so-called rubber concrete, and thereupon presents a way of modification of waste rubber to construction articles. The conventional cement concrete is made by mixing cement with sand and pebbles, but the rubber concrete proposed here virtually excludes cement completely. The manufacturing process of rubber concrete can be divided into two methods, which are designated for dry and wet processes, but this article focused just on the dry process. The physical properties of rubber composite increased with the silane treatment of added aggregates, but the volume of the aggregate might not be a critical factor affecting the compressive strength in the range of the aggregate contents used in this study, that is, the interfacial adhesion between the matrix rubber and the aggregates was a key factor to improve the mechanical properties of rubber concrete. The compressive strength of rubber concrete was about 89 MPa and the Poisson's ratio, which is the ratio of compressive-to-tensile strength, was 5.5%. From the viewpoint of the compressive strength and the Poisson's ratio, rubber concrete had better properties than those of conventional cement concrete. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 35–40, 1999

Introductory behavior of rubber concrete

This article introduces a new type of concrete, the so-called rubber concrete, and thereupon presents a way of modification of waste rubber to construction articles. The conventional cement concrete is made by mixing cement with sand and pebbles, but the rubber concrete proposed here virtually excludes cement completely. The manufacturing process of rubber concrete can be divided into two methods, which are designated for dry and wet processes, but this article focused just on the dry process. The physical properties of rubber composite increased with the silane treatment of added aggregates, but the volume of the aggregate might not be a critical factor affecting the compressive strength in the range of the aggregate contents used in this study, that is, the interfacial adhesion between the matrix rubber and the aggregates was a key factor to improve the mechanical properties of rubber concrete. The compressive strength of rubber concrete was about 89 MPa and the Poisson's ratio, which is the ratio of compressive-to-tensile strength, was 5.5%. From the viewpoint of the compressive strength and the Poisson's ratio, rubber concrete had better properties than those of conventional cement concrete. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 35–40, 1999