Modeling for bond-constitutive relationships of FRP rebars to concrete matrix

2020 ◽  
Vol 263 ◽  
pp. 120654
Author(s):  
Lihua Huang ◽  
Jian Chen ◽  
Jiting Qu ◽  
Qianqian Dai
Keyword(s):  
Constitutive Relationships ◽  
Concrete Matrix

Adding an expansive agent to increase the toughness of steel fibre reinforced concrete

2019 ◽  
Vol 26 (4) ◽  
pp. 197-208
Author(s):  
Leo Gu Li ◽  
Albert Kwok Hung Kwan
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
The Other ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Compressive Properties ◽  
Shrinkage Cracking ◽  
Steel Fibre Reinforced Concrete ◽  
Expansive Agent ◽  
Concrete Matrix

Previous research studies have indicated that using fibres to improve crack resistance and applying expansive agent (EA) to compensate shrinkage are both effective methods to mitigate shrinkage cracking of concrete, and the additions of both fibres and EA can enhance the other performance attributes of concrete. In this study, an EA was added to fibre reinforced concrete (FRC) to produce concrete mixes with various water/binder (W/B) ratios, steel fibre (SF) contents and EA contents for testing of their workability and compressive properties. The test results showed that adding EA would slightly increase the superplasticiser (SP) demand and decrease the compressive strength, Young’s modulus and Poisson’s ratio, but significantly improve the toughness and specific toughness of the steel FRC produced. Such improvement in toughness may be attributed to the pre-stress of the concrete matrix and the confinement effect of the SFs due to the expansion of the concrete and the restraint of the SFs against such expansion.

Properties of Concrete Containing Scrap-Tire Chips

2011 ◽  
Vol 399-401 ◽  
pp. 1251-1256 ◽  
Author(s):  
Wai Ching Tang ◽  
Hong Zhi Cui ◽  
Yiu Lo
Keyword(s):  
Environmental Issues ◽  
Normal Weight ◽  
Scrap Tire ◽  
Scrap Tires ◽  
Bonding Agents ◽  
Normal Weight Concrete ◽  
Tire Chips ◽  
Increase With Increase ◽  
The World ◽  
Concrete Matrix

Nowadays, one of the most essential environmental issues around the world is to deal with the scrap tire problem. Tires that are used, rejected or unwanted are classified as scrap tires and need to be managed responsibly. In this paper, the scrap tires were shredded into pieces and used to mix with normal weight concrete. Extensive laboratory tests were carried out and the focus of this paper was to characterize the mechanical and permeability properties of concrete containing scrap tires. The main parameters studied were chipped tire content and size. The results showed that the scrap-tire chips without adding special bonding agents apparently showed an even distribution in the mortar and concrete matrix. The elastic modulus, compressive and tensile strengths of scrap tire concrete in general were found lower than that of the control concrete and the differences became significant when the content and size of chipped tires in the mix were increased. Besides, the coefficients of water permeability of concrete were found to increase with increase of chipped tires in the mix.

Improved Early-Age Cohesive Stress Response from Hybrid Blends of Micro and Macro Fibers

2021 ◽  
Vol 1046 ◽  
pp. 1-7
Author(s):  
Manjunath V. Bhogone ◽  
Kolluru V.L. Subramaniam
Keyword(s):  
Reinforced Concrete ◽  
Stress Response ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Early Age ◽  
Fiber Reinforced ◽  
Cohesive Stress ◽  
Concrete Matrix ◽  
Polypropylene Fiber Reinforced Concrete

The fracture response of macro polypropylene fiber reinforced concrete (PPFRC) and hybrid blend of macro and micro polypropylene fiber reinforced concrete (HyFRC) are evaluated at 1, 3, 7 and 28 days. There is an improvement in the early-age fracture response of HyFRC compared to PPFRC. The changing cohesive stress-crack separation relationship produced by ageing of the concrete matrix is determined from the fracture test responses. An improved early-age cohesive stress response is obtained from the hybrid blend containing micro and macro fibers. The hybrid fiber blend also has a higher tensile strength at early age when compared to an identical volume fraction of macro polypropylene fibers.

Mechanical and microstructural behavior of concrete containing marble and nano silica

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gaurav Sancheti ◽  
Vikram Singh Kashyap ◽  
Jitendra Singh Yadav
Keyword(s):  
Mechanical Properties ◽  
Nano Silica ◽  
Microstructural Characteristics ◽  
Content Type ◽  
X Ray ◽  
Static Modulus ◽  
Marble Dust ◽  
Microstructural Behavior ◽  
Static Modulus Of Elasticity ◽  
Concrete Matrix

Purpose The purpose of this study is to perform comprehensive investigation to assess the mechanical properties of nano-modified ternary cement concrete blend. Nano silica (NS) (1%, 2% and 3%) and waste marble dust powder (MD) (5%, 10% and 15%) was incorporated as a fractional substitution of cement in the concrete matrix. Design/methodology/approach In this experimental study, 10 cementitious blends were prepared and tested for compressive strength, flexural strength, splitting tensile strength and static modulus of elasticity. The microstructural characteristics of these blends were also explored using a scanning electron microscope along with energy dispersive spectroscopy and X-ray reflection. Findings The results indicate an enhancement in mechanical properties and refinement in pore structure due to improved pozzolanic activities of NS and the filling effect of MD. Originality/value To the best of the authors’ knowledge, no study has reported the mechanical and microstructural behavior of concrete containing marble and NS.

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