Mechanical properties and freeze-thaw resistances of bronze-concrete composites

2021 ◽  
Vol 12 (2) ◽  
pp. 39
Author(s):  
Tuba Bahtli ◽  
Nesibe Sevde Ozbay

Studies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete.

2019 ◽  
Vol 11 (0) ◽  
pp. 1-5
Author(s):  
Deividas Augutis ◽  
Džigita Nagrockienė

Materials used for the study: Portland cement CEM I 42,5 R, 0/4 fraction sand, 4/16 fraction gravel, biofuel fly ash, superplastizer ViscoCrete D187 (V) and water. Seven compositions of concrete were designed by replacing 0%, 5%, 10%, 15%, 20%, 25% and 30% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. Studies have shown that the increase of biofuel fly ash content up to 15% increases concrete density and compressive strengh after 28 days of curing, compressive strength, ultrasonic pulse velocity, closed porosity, concrete forecasted freeze-thaw cycles and decreases water absorbtion, open porosity.


2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Tuba Bahtlı ◽  
Nesibe Sevde Özbay

In this study, the effects of finely-milled bronze and waste tire on the mechanical properties of concrete have been investigated. Approximately 2.5% and 5% by weight for each additive (bronze sawdust and waste tire) were added to dry concrete. The open porosity, density, compressive strength values of cured concrete have been determined. In addition, the Schmidt rebound hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, were applied. The microstructure and fracture surfaces of these materials were characterized by scanning electron microscopy (SEM). It was observed that the density of pure concrete was 2.35 g/cm3 while the density was 2.19 g/cm3 for a C+5%B+5%T material. Similarly, pure concrete had an almost three times better compressive strength and a two times better SRH value than those of the C+5%B+5%T material. The density and mechanical properties of concrete materials containing bronze and waste tire decreased due to micro crack formations, weak bonding and deep cracks forming especially between the concrete and additives.


Ultrasonics ◽  
2015 ◽  
Vol 60 ◽  
pp. 33-40 ◽  
Author(s):  
Emilia Vasanelli ◽  
Donato Colangiuli ◽  
Angela Calia ◽  
Maria Sileo ◽  
Maria Antonietta Aiello

2017 ◽  
Vol 80 (1) ◽  
Author(s):  
Ruhal Pervez Memon ◽  
Lemar Achekzai ◽  
Abdul Rahman Mohd. Sam ◽  
A. S. M. Abdul Awal ◽  
Uroosa Memon

The aim of this study was to shows the behavior of sawdust concrete at elevated temperature. Sawdust is considered as waste material but nowadays this waste material is utilized in the construction of the building as sawdust concrete. Sawdust is a by-product of wood which is generally used in the production of lightweight concrete, possessing low thermal conductivity. In this study sawdust concrete was made at three different proportions of cement and sawdust 1:1, 1:2, 1:3 by volume. At these proportions, the physical and mechanical properties such as density, workability, strength, fire resistance, mass loss, ultrasonic pulse velocity and residual strength were investigated after 28 days of curing. It was found that with the increment in the amount of sawdust, the workability and strength decreases, however in terms of fire resistance, concrete with lower amount of sawdust performed well. Considering the overall physical and mechanical properties, sawdust concrete can be used in building construction. 


2021 ◽  
Vol 5 (6) ◽  
pp. 146
Author(s):  
Mahmoud Abu-Saleem ◽  
Yan Zhuge ◽  
Reza Hassanli ◽  
Mark Ellis ◽  
Md Mizanur Rahman ◽  
...  

Different types of recycled plastic have been used in concrete and most studies have focused on the behaviour of a single type of plastic. However, separating plastic wastes increases the cost and time of processing. To tackle this problem, this research presents an experimental investigation to determine the effect of incorporating different combinations of three types of recycled plastic waste aggregates—Polyethylene terephthalate (PET), High Density Polyethylene (HDPE) and Polypropylene (PP)—at different replacement ratios of coarse aggregate on physical and mechanical properties of concrete. The combinations include two plastic types at 10% and 20% replacement ratios and three plastic types at 15% and 30% replacement ratios. The performance of the plastic concrete was assessed based on various physical and mechanical properties including workability, fresh and dry densities, air content, compressive, indirect tensile and flexural strengths, modulus of elasticity, stress-strain behaviour and ultrasonic pulse velocity. It is found that the workability of Mixed Recycled Plastic Concrete (MRPC) at a low replacement rate is independent of the type of plastic. The minimum reduction in the compressive strength, indirect tensile and modulus of elasticity were achieved by R3 (PET + PP) at 10% replacement, while R5 (HDPE + PP) at 10% replacement achieved the highest flexural strength and ultrasonic pulse velocity values. The findings suggest that the mixed recycled plastics have a good possibility to partially replace coarse aggregates in concrete which will benefit the plastics recycling community and environment. Furthermore, the study will provide guidance to the concrete industry concerning the effect of the implementation of unsorted mixed types of plastic as coarse aggregates in the production of concrete.


2017 ◽  
Vol 5 (2) ◽  
pp. 109 ◽  
Author(s):  
Metin Aşcı ◽  
İsmail Kaplanvural ◽  
Ahmet Karakaş ◽  
Özgün Kamil Şahin ◽  
Cengiz Kurtuluş

Correlation of physical and mechanical properties with ultrasonic pulse velocities (UPV) of sandstones in Çenedağ, Kocaeli-Turkey, NW was performed in this study. Physical and mechanical properties were defined and the relationships among the uniaxial compressive strength (UCS), porosity, void ratio, point load strength index Is(50),Schmidt hardness (RN) and bulk mass density by weight with ultrasonic pulse velocity of pink and cream colored sandstone unit of Lower Ordovician Çenedağ formation were investigated. In the scope of this research, 16 sandstone specimens were collected from various locations of Çenedağ formation in Çenedağ-Kocaeli, Turkey and laboratory experiments were implemented. Later, the statistical correlations were performed by regression analysis to evaluate the relationships between these properties and ultrasonic pulse velocity. Reasonably good correlations were determined between the UPV and physical and mechanical properties.


2012 ◽  
Vol 66 (4) ◽  
pp. 609-617 ◽  
Author(s):  
Dragica Jevtic ◽  
Dimitrije Zakic ◽  
Aleksandar Savic

The results of experimental investigations performed on cement based composites made with addition of recycled rubber as a partial replacement of natural river aggregate are presented in this paper. Different properties of cement based mortar were analyzed, both in fresh and in hardened state. Tested properties in the fresh state included: density, consistency and volume of entrained air. In the hardened state, the following properties were tested: density, mechanical properties (compressive and flexural strength), modulus of elasticity, adhesion to concrete substrate, water absorption, freeze-thaw resistance and ultrasonic pulse velocity. The obtained results indicate that recycled rubber can be successfully applied as a partial replacement of natural river aggregate in cement based composites, in accordance with the sustainable development concept. The investigation showed that physical-mechanical properties of cementituous composites depend to a great extent on the percentage of replacement of natural river aggregate with recycled rubber, especially when the density, strength, adhesion and freeze-thaw resistance are concerned. The best results were obtained in the freeze-thaw resistance of such composites.


Author(s):  
Zita Pápay ◽  
Ákos Török

This paper focuses on the effect of high temperature on the mechanical properties of a porous limestone that is widely used as dimension stone in Hungary. The changes in physical properties of 3 types of porous limestone were analyzed at 22 °C, 300 °C and 600 °C, respectively. The limestone specimens were also subjected to freeze-thaw cycles to assess the other extrinsic factor that influences the behavior. Parameters such as material density, bulk density, ultrasonic pulse velocity and tensile strength were measured and compared in different test conditions. The tests results indicate that fabric differences significantly influences the durability of tested limestones. Bioclastic grainstone is more frost resistant that ooidal grainstone or bioclastic packstone, but heating seems to reduce the pulse velocity and tensile strength of all tested limestone. It is suggested that cyclic freezing-thawing reduces the strength depending on the micro-fabric, while heating to 600 °C and the reduction of strength is less controlled by the fabric of the porous limestone.


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