Bond Behavior between Tuff and Fired-Clay Brick Masonry Blocks and SRG Composites

2019 ◽  
Vol 817 ◽  
pp. 118-125
Author(s):  
Giulia Baietti ◽  
Elisa Franzoni ◽  
Giovanni Quartarone ◽  
Alberto Fregni ◽  
Christian Carloni

This paper presents the results of single-lap direct shear tests on steel reinforced grout (SRG) strips bonded to fired-clay brick and tuff masonry blocks. For this experimental campaign, fifteen masonry blocks were constructed and reinforced with SRG composite strips. Fired-clay bricks and tuff blocks herein employed were collected from demolished historical structures in Modena and Naples (Italy), respectively. Eight out of fifteen blocks were subjected to an artificial weathering procedure to induce salt crystallization, and therefore reproduce the degradation conditions that the buildings could be subjected to during their life. Bond behavior of unconditioned strengthened specimens (i.e. SRG-masonry joints) was compared with the behavior of conditioned joints. Salt distribution, open porosity, and water absorption of brick and tuff masonry units as well as of the SRG composite matrix were analyzed to understand if and how the salt crystallization influenced the adhesion between the SRG strip and the block.

2020 ◽  
Vol 4 (4) ◽  
pp. 182
Author(s):  
Luciano Ombres ◽  
Salvatore Verre

In the paper, the bond between a composite strengthening system consisting of steel textiles embedded into an inorganic matrix (steel reinforced grout, SRG) and the concrete substrate, is investigated. An experimental investigation was carried out on medium density SRG specimens; direct shear tests were conducted on 20 specimens to analyze the effect of the bond length, and the age of the composite strip on the SRG-to-concrete bond behavior. In particular, the tests were conducted considering five bond length (100, 200, 250, 330, and 450 mm), and the composite strip’s age 14th, 21st, and 28th day after the bonding. Test results in the form of peak load, failure modes and, bond-slip diagrams were presented and discussed. A finite element model developed through commercial software to replicate the behavior of SRG strips, is also proposed. The effectiveness of the proposed numerical model was validated by the comparison between its predictions and experimental results.


CivilEng ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 68-86
Author(s):  
Karrar Al-Lami ◽  
Tommaso D’Antino ◽  
Pierluigi Colombi

Fiber-reinforced cementitious matrix (FRCM) and steel-reinforced grout (SRG) have been increasingly applied as externally bonded reinforcement to masonry members in the last few years. Unlike fiber-reinforced polymer (FRP), FRCM and SRG have good performance when exposed to (relatively) high temperature and good compatibility with inorganic substrates, and they can be applied to wet surfaces and at (reasonably) low temperatures. Although numerous studies investigated the mechanical properties and bond performance of various FRCM and SRG, new composites have been developed recently, and their performance still needs to be assessed. In this study, the bond behavior of three FRCM composites and one SRG composite applied to a masonry substrate is investigated. Sixteen single-lap direct shear tests (four tests for each composite) are performed. The FRCM studied comprised one layer of carbon, PBO (polyparaphenylene benzobisoxazole), or alkali-resistant (AR)-glass bidirectional textile embedded within two cement-based matrices. The SRG composite comprised one layer of a unidirectional stainless-steel cord textile embedded within a lime-based matrix. The results show a peculiar bond behavior and failure mode for each composite. Based on these results, the behavior of the carbon and PBO FRCM is modeled solving the bond differential equation with a trilinear cohesive material law (CML).


2021 ◽  
Vol 13 (15) ◽  
pp. 8201
Author(s):  
Lihua Li ◽  
Han Yan ◽  
Henglin Xiao ◽  
Wentao Li ◽  
Zhangshuai Geng

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.


Silicon ◽  
2021 ◽  
Author(s):  
Ghita El Boukili ◽  
Mohamed Ouakarrouch ◽  
Mahdi Lechheb ◽  
Fatima Kifani-Sahban ◽  
Asmae Khaldoune

2017 ◽  
Vol 45 (6) ◽  
pp. 674-687 ◽  
Author(s):  
Gary John Fowmes ◽  
Neil Dixon ◽  
Liwei Fu ◽  
Catalin Alexandru Zaharescu

2009 ◽  
Author(s):  
Andrés D. Orlando ◽  
Daniel M. Hanes ◽  
Hayley H. Shen ◽  
Masami Nakagawa ◽  
Stefan Luding

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