scholarly journals Effectiveness of Saturated Coral Aggregate and Shrinkage Reducing Admixture on the Autogenous Shrinkage of Ultrahigh Performance Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Jinming Liu ◽  
Zhongwen Ou ◽  
Jinchuan Mo ◽  
Yuzhuo Chen ◽  
Tong Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Quartz Sand ◽  
Autogenous Shrinkage ◽  
Internal Curing ◽  
Property Development ◽  
Replacement Ratio ◽  
Shrinkage Reducing Admixture ◽  
Autogenous Deformation

The use of saturated coral aggregate (SCA) as practical replacement of quartz sand has been shown to effectively mitigate the autogenous shrinkage in ultrahigh performance concrete (UHPC). The autogenous deformation, the compressive strength, the flexural strength, and the hydration property development of paste with different shrinkage means were tested. Three different methods were evaluated to mitigate the autogenous shrinkage: SCA, shrinkage reducing admixture (SRA), and the mixture of SCA and SRA (SRA-SCA). It was found that SCA and SRA have all the effective ways to reduce the shrinkage deformation, and SRA-SCA was the most effective in mitigating the shrinkage. The autogenous shrinkage of UHPC was restrained, when the SCA dosage was 44%, the SRA dosage was 0.8%, the SCA content was 26%, the SRA dosage was 2.4%, the SCA content was 18%, the SRA content was 2.4%, or the SCA dosage was 26%. The mechanical properties were deteriorated by the addition of SCA, while the compressive strength was still higher than 90 MPa at 28 days even though the replacement ratio of SCA was up to 50%. Furthermore, internal curing by means of SCA was proved to be a successful way to mitigate autogenous shrinkage, after the tests.

scholarly journals The Influence of Nano-SiO2 and Recycled Polypropylene Plastic Content on Physical, Mechanical, and Shrinkage Properties of Mortar

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Haiming Chen ◽  
Yangchen Xu ◽  
Donglei Zhang ◽  
Lingxia Huang ◽  
Yuntao Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Water Absorption ◽  
Construction Material ◽  
Autogenous Shrinkage ◽  
Physical And Mechanical Properties ◽  
Plastic Waste ◽  
Partial Replacement ◽  
Interfacial Zone

This work is aimed to study the possibility of recycling plastic waste (polypropylene (PP)) as aggregate instead of sand in the manufacturing of mortar or concrete. For this, an experimental study was carried out to evaluate the influence of nano-SiO2 and recycled PP plastic particles' content on physical, mechanical, and shrinkage properties and microstructure of the mortars with recycled PP plastic particles. The sand is substituted with the recycled PP plastic particles at dosages (0%, 20%, 40%, and 60% by volume of the sand). The nano-SiO2 content is 5% by weight of cement. The physical (porosity, water absorption, and density), mechanical (compressive and flexural strength) and shrinkage properties of the mortars were evaluated, and a complementary study on microstructure of the interface between cementitious matrix and PP plastic particles was made. The measurements of physical and mechanical properties showed that PP-filled mortar had lower density and better toughness (higher ratio of flexural strength to compressive strength). However, the compressive strength and flexural strength of PP-filled mortar is reduced, and the porosity, water absorption, autogenous shrinkage, and dry shrinkage increased as compared to normal cement mortar. The addition of nano-SiO2 reduced the porosity, water absorption, and drying shrinkage of PP-filled mortar and effectively improved the mechanical properties, but increased its autogenous shrinkage. A microscopic study of the interfacial zone (plastic-binder) has shown that there is poor adhesion between PP plastic particles and cement paste. From this work, it is found that recycled PP plastic waste has a great potential to be a construction material. It can be used as partial replacement of natural aggregates instead.

scholarly journals INFLUENCE OF QUARTZ SAND AND MARBLE-SLUDGE POWDER AS REPLACEMENTS FOR FINE AGGREGATE ON THE MECHANICAL PROPERTIES OF HIGH-STRENGTH SELF-COMPACTING CONCRETE

2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Dhanalakshmi A ◽  
M. Shahul Hameed
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Bond Strength ◽  
Quartz Sand ◽  
High Strength ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Marble Sludge

High-strength self-compacting concrete (HSSCC) is widely used as an eco-effective structure that is more durable than traditional cement that is more prone to demolitions and damage. One of today’s notable innovations is self-compacting concrete (SCC). The variety of materials and the utilization of siphons encourage the concrete’s use, which is significant. The worries about complex pieces are understandable due to the ease, with which precarious projecting zones are formed. This article presents high-strength self-compacting concrete, including quartz sand (QS) and marble-sludge powder (MSP) used as a partial replacement of fine aggregate (M sand). The substitution impact of QS and MSP on the strength of HSSCC is investigated. Further, V-funnel, L-box, slump flow, J-ring and slump cone are used to investigate the chemical, physical and mechanical properties such as splitting tensile strength, compressive strength, bond strength and flexural strength. The replacement of fine aggregate with 15 % of marble-sludge powder and 45 % of quartz sand (HSSCC concrete) gives an unprecedented outcome in the form of solidity and consistency. The findings show that the HSSCC 9 mix exhibits the compressive strength, splitting tensile strength, flexural strength and, more noteworthy, bond strength of 82.25 MPa, 8.10 MPa, 27.10 MPa and 11.89 MPa, respectively.

scholarly journals Preparation of Electric- and Magnetic-Activated Water and Its Influence on the Workability and Mechanical Properties of Cement Mortar

2021 ◽  
Vol 13 (8) ◽  
pp. 4546
Author(s):  
Kaiyue Zhao ◽  
Peng Zhang ◽  
Bing Wang ◽  
Yupeng Tian ◽  
Shanbin Xue ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Cement Mortar ◽  
Environmental Issues ◽  
Chemical Admixtures ◽  
Untreated Water ◽  
Alternating Voltage

Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

scholarly journals Assessment of the Rheological and Mechanical Properties of Geopolymer Concrete Comprising Fly Ash and Fluid Catalytic Cracking Residue as Aluminosilicate Precursor

2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Catalytic Cracking ◽  
Fluid Catalytic Cracking ◽  
High Alumina ◽  
Geopolymer Concrete ◽  
Sem Images

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.

Research on Mechanical Properties of Crumb Rubber Concrete

2011 ◽  
Vol 477 ◽  
pp. 290-295 ◽  
Author(s):  
Li Bo Bian ◽  
Shao Min Song
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Apparent Density ◽  
Crumb Rubber ◽  
Fatigue Performance ◽  
Brittleness Index ◽  
Mixing Ratio ◽  
Rubber Concrete

Considering large number production of the abandoned tyres and the question of the concrete with mixture of crumb rubber，the mainly task of this paper is to study the mechanical properties of different mixing ratio concrete with vary volume of crumb rubber. The results showed that the workability, apparent density, compressive strength, flexural strength and brittleness index decrease as the increase of crumb rubber. While the anti-crack performance and anti-fatigue performance can be improved. The wear-resistance properties are a little lower than common concrete.

Effect of using magnetic water on the mechanical properties of concrete exposed to elevated temperature

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wasim Barham ◽  
Ammar AL-Maabreh ◽  
Omar Latayfeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Flexural Strength ◽  
Tap Water ◽  
Splitting Tensile Strength ◽  
Content Type ◽  
Normal Water ◽  
Magnetic Water

PurposeThe influence of using magnetic water instead of tap water in the mechanical properties of the concrete exposed to elevated temperatures was investigated. Two concrete mixes were used and cast with the same ingredients. Tap water was used in the first mix and magnetic water was used in the second mix. A total of 48 specimens were cast and divided as follows: 16 cylinders for the concrete compressive strength test (8 samples for each mix), 16 cylinders for the splitting tensile strength (8 specimens for each mix) and 16 beams to test the influences of magnetized water on the flexural strength of concrete (8 specimens for each mixture). Specimens were exposed to temperatures of (25 °C, 200 °C, 400 °C and 600 °C). The experimental results showed that magnetic water highly affected the mechanical properties of concrete. Specimens cast and curried out with magnetic water show higher compressive strength, splitting tensile strength and flexural strength compared to normal water specimens at all temperatures. The relative strength range between the two types of water used was 110–123% for compressive strength and 110–133% for splitting strength. For the center point loading test, the relative flexural strength range was 118–140%. The use of magnetic water in mixing concrete contribute to a more complete hydration process.Design/methodology/approachExperimental study was carried out on two concrete mixes to investigate the effect of magnetic water. Mix#1 used normal water as the mixing water, and Mix#2 used magnetic water instead of normal water. After 28 days, all the samples were taken out of the tank and left to dry for seven days, then they were divided into different groups. Each group was exposed to a different temperature where it was placed in a large oven for two hours. Three different tests were carried out on the samples, these tests were concrete compressive strength, flexural strength and splitting tensile strength.FindingsExposure of concrete to high temperatures had a significant influence on concrete mechanical properties. Specimens prepared using magnetic water showed higher compressive strength at all temperature levels. The use of magnetic water in casting and curing concrete can increase the compressive strength by 23%. Specimens prepared using magnetic water show higher splitting tensile strength at all temperatures up to 33%. The use of magnetic water in casting and curing can strengthen and increase concrete resistance to high temperatures, a significant enhancement in flexural strength at all temperatures was found with a value up to 40%.Originality/valuePrevious research proved the advantages of using magnetic water for improving the mechanical properties of concrete under normal conditions. The potential of using magnetic water in the concrete industry in the future requires conducting extensive research to study the behavior of magnetized concrete under severe conditions to which concrete structures may be subjected to. These days, there are attempts to obtain stronger concrete with high resistance to harsh environmental conditions without adding new costly ingredients to its main mixture. No research has been carried out to investigate the effect of magnetic water on the mechanical properties of concrete exposed to elevated temperature. The main objective of this study is to evaluate the effect of using magnetic water on the mechanical properties of hardened concrete subjected to elevated temperature.

scholarly journals The Mechanical Properties of Steel-Polypropylene Fibre Composites Concrete (HyFRCC)

2015 ◽  
Vol 773-774 ◽  
pp. 949-953 ◽  
Author(s):  
Izni Syahrizal Ibrahim ◽  
Wan Amizah Wan Jusoh ◽  
Abdul Rahman Mohd Sam ◽  
Nur Ain Mustapa ◽  
Sk Muiz Sk Abdul Razak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Volume Fraction ◽  
Concrete Strength ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Polypropylene Fibre ◽  
Experimental Results

This paper discusses the experimental results on the mechanical properties of hybrid fibre reinforced composite concrete (HyFRCC) containing different proportions of steel fibre (SF) and polypropylene fibre (PPF). The mechanical properties include compressive strength, tensile strength, and flexural strength. SF is known to enhance the flexural and tensile strengths, and at the same time is able to resist the formation of macro cracking. Meanwhile, PPF contributes to the tensile strain capacity and compressive strength, and also delay the formation of micro cracks. Hooked-end deformed type SF fibre with 60 mm length and fibrillated virgin type PPF fibre with 19 mm length are used in this study. Meanwhile, the concrete strength is maintained for grade C30. The percentage proportion of SF-PPF fibres are varied in the range of 100-0%, 75-25%, 50-50%, 25-75% and 0-100% of which the total fibre volume fraction (Vf) is fixed at 0.5%. The experimental results reveal that the percentage proportion of SF-PPF fibres with 75-25% produced the maximum performance of flexural strength, tensile strength and flexural toughness. Meanwhile, the percentage proportion of SF-PPF fibres with 100-0% contributes to the improvement of the compressive strength compared to that of plain concrete.

scholarly journals Mechanical Properties and Microstructural Features using Stone Dust as a Partial Replacement of Sand

2019 ◽  
Vol 8 (6) ◽  
pp. 5232-5237
Keyword(s):  
Mechanical Properties ◽  
Economic Growth ◽  
Sustainable Development ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Natural Resources ◽  
Strength Test ◽  
Partial Replacement ◽  
Test Results ◽  
Stone Dust

Today’s world is always leads to development in technology as well as the economic growth though sometime these will affect the environment badly. That’s why world environmental commission coined the termed called sustainable development where development takes place without hampering the others’ needs. Concrete industry is rapidly growing industry in India which consumes lots of natural resources during the production of concrete. Here Stone dust is used as a sustainable material in place of sand partially. M25 grade of concrete has been chosen for the experiments. Different mechanical properties of concrete like compressive strength, Split tensile, flexural strength etc. and Microstructural features like SEM, EDX have been included in this study. Compressive Strength and flexural strength test results shown the increase in the strength. Sulphate Resistance Properties have been tested by curing the cubes in the MgSO4 solution and increase in weight has been observed. Similarities are found in the SEM pictures

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