scholarly journals Mechanical Properties of Lightweight Concrete Using Recycled Cement-Sand Brick as Coarse Aggregates Replacement

2018 ◽  
Vol 34 ◽  
pp. 01029
Author(s):  
Ilya Joohari ◽  
Nor Farhani Ishak ◽  
Norliyati Mohd Amin
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Mechanical Testing ◽  
Lightweight Concrete ◽  
Control Sample ◽  
Density Measurement ◽  
Flexural Test ◽  
Coarse Aggregates ◽  
Optimum Proportion ◽  
Natural Aggregates

This paper presents the result of replacing natural course aggregate with recycled cement-sand brick (CSB) towards the mechanical properties of concrete. Natural aggregates were used in this study as a control sample to compare with recycled coarse aggregates. This study was also carried to determine the optimum proportion of coarse aggregates replacement to produce lightweight concrete. Besides, this study was conducted to observe the crack and its behaviour development during the mechanical testing. Through this study, four types of concrete mixed were prepared, which were the control sample, 25%, 50% and 75% replacement of CSB. The test conducted to determine the effectiveness of recycled CSB as coarse aggregates replacement in this study were slump test, density measurement, compression test, and flexural test and. The strength of concrete was tested at 7 days and 28 days of curing. From the results obtained, the optimum proportion which produced the highest strength is 25% replacement of recycled CSB. The compressive and flexural strength has decreased by 10%-12% and 4%-34% respectively compared to the control sample. The presence of recycled coarse aggregates in sample has decreased the density of concrete by 0.8%-3% compared to the control sample.

scholarly journals 24-hour Fire Produced Effect on Reinforced Recycled Aggregates Concrete Beams

2019 ◽  
Vol 9 (3) ◽  
pp. 4213-4217 ◽  
Author(s):  
A. H. Buller ◽  
M. Oad ◽  
B. A. Memon ◽  
S. Sohu
Keyword(s):  
Flexural Strength ◽  
Concrete Beams ◽  
Testing Machine ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Recycled Aggregates ◽  
Equal Proportion ◽  
Load Testing ◽  
Coarse Aggregates ◽  
Natural Aggregates

In this article, the effect of prolonged fire (24-hour duration) on reinforced concrete beams made with recycled aggregates from demolished concrete was experimentally investigated. Demolished concrete was used recycled coarse aggregates in equal proportion with natural coarse aggregates. Normal and rich mix concrete with water-cement ratio equal to 0.54 were used. As a control specimen, beams with all-natural aggregates were also cast to compare with the results of the proposed beams. All beams were cured for 28 days and exposed to fire at 1000°C in an oven for 24 hours. After the elapse of this fire period, the beams were allowed to air cool, followed by testing till failure in a universal load testing machine. Comparison of the test results shows that rich mix concrete beams more reduction in flexural strength, more increase in maximum load carrying capacity and deflection than normal mix beams. The maximum reduction in flexural strength was 32.41% for beams cast with 50% RCA and rich mix. Although the fire duration used in this study is rare, yet the outcome provides guidelines for taking proper decisions for retrofitting/strengthening of the fire affected structure before putting it back in service.

scholarly journals Influence of Glass Fibers on Mechanical Properties of Concrete with Recycled Coarse Aggregates

2019 ◽  
Vol 5 (5) ◽  
pp. 1007-1019 ◽  
Author(s):  
Babar Ali ◽  
Liaqat Ali Qureshi ◽  
Ali Raza ◽  
Muhammad Asad Nawaz ◽  
Safi Ur Rehman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Glass Fibers ◽  
Construction Material ◽  
Concrete Compressive Strength ◽  
Coarse Aggregates ◽  
Highly Sensitive

Despite plain cement concrete presenting inferior performance in tension and adverse environmental impacts, it is the most widely used construction material in the world. Consumption of fibers and recycled coarse aggregates (RCA) can add ductility and sustainability to concrete. In this research, two mix series (100%NCA, and 100%RCA) were prepared using four different dosages of GF (0%GF, 0.25%GF, 0.5%GF, and 0.75%GF by volume fraction).  Mechanical properties namely compressive strength, splitting tensile strength, and flexural strength of each concrete mixture was evaluated at the age of 28 days. The results of testing indicated that the addition of GF was very useful in enhancing the split tensile and flexural strength of both RCA and NCA concrete. Compressive strength was not highly sensitive to the addition of GF. The loss in strength that occurred due to the incorporation of RCA was reduced to a large extent upon the inclusion of GF. GF caused significant improvements in the split tensile and flexural strength of RCA concrete. Optimum dosage of GF was determined to be 0.25% for NCA, and 0.5% for RCA concrete respectively, based on the results of combined mechanical performance (MP).

Influence of Fiber’s Surface State on Mechanical Properties and Fiber-Matrix Interaction of CFRP

2013 ◽  
Vol 690-693 ◽  
pp. 323-328
Author(s):  
J. J. Sha ◽  
Y.X. Zhang ◽  
J. Li ◽  
J. X. Dai ◽  
Z. Q. Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Surface State ◽  
Elevated Temperatures ◽  
Fiber Surface ◽  
Flexural Test ◽  
Matrix Interaction ◽  
Fiber Matrix

In order to investigate the influence of carbon fiber’s surface state on the mechanical properties and the fiber-matrix interaction of CFRP, the change of surface state was achieved by thermal treatment of carbon fibers at elevated temperatures, and the surface state was characterized by XPS. The mechanical properties were measured from the flexural test. The CFRP reinforced with 600 °C treated fabrics containing the highest reactive functional groups, showed the highest flexural strength and modulus. But in the case of CFRP reinforced with 1500 °C treated fabrics containing the lowest reactive functional groups, exhibited the lowest flexural strength and modulus. Combining the mechanical properties with the microstructure analysis, the results indicated that the fiber-matrix interaction (strong or weak) depends on the relative percentage of reactive functional groups present on the carbon fiber surface.

scholarly journals Synthesis and Characteristics of Local Fly Ash Based Geopolymers Mixed with Natural Aggregates

2019 ◽  
Vol 70 (4) ◽  
pp. 1262-1267 ◽  
Author(s):  
Dumitru Doru Burduhos Nergis ◽  
Petrica Vizureanu ◽  
Ofelia Corbu
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Flexural Strength ◽  
Alkaline Solution ◽  
Development Process ◽  
Rapid Development ◽  
Point Of View ◽  
Construction Sector ◽  
New Materials ◽  
Natural Aggregates

Global industrialization generates large amount of waste which strongly affects the depositing areas and the living creatures from the surroundings. In the same time, the construction sector meets an exponential development process, resulting in materials and construction areas increase. Therefore, the need of new materials was felt worldwide. One solution that knew a rapid development, especially in this sector, was to obtain new eco-friendly materials through a mechanism called geopolymerization. True this powerful chemical reaction between a waste, rich in aluminum and silicon, and a strong alkaline solution, a tetragonal structure of Al-O-Si is obtained that possess properties comparable to those of Portland cement-based concrete. In the present paper the effect of aggregates on local fly ash based geopolymers is analyzed from the structure and mechanical properties point of view. According to this study, the aggregates strongly influence the density, compression strength and flexural strength at any age of samples.

White Clay Ceramic Tableware Waste as Coarse Aggregate in Concrete - Some Mechanical Properties and Durability against Fire and Sulfate Attack

2021 ◽  
Vol 895 ◽  
pp. 121-129
Author(s):  
Ameer Ghayyib Talib ◽  
Qusay A. Jabal ◽  
Waseem Haleem Al-Baghdadi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Fire Resistance ◽  
Good Resistance ◽  
Ordinary Concrete ◽  
Coarse Aggregates ◽  
Water Effects ◽  
Concrete Mechanical Properties ◽  
Clay Ceramics ◽  
White Clay

The aim of study is to produce durable structural concrete by using waste ceramics with specified type (white clay ceramics) as coarse aggregates in concrete. Mechanical properties were studied, the study also show good resistance to fire resistance for concrete contains ceramics as coarse aggregates compared with normal aggregates concrete, good mechanical properties such as compressive, tensile, and flexural strength. Results of study gave 17.5% increment in compressive strength by using 100% replacement of waste ceramic, flexural strength increased with 27.8% increment. Study also show less reduction in strength due to fire resistance by using waste ceramics compared to ordinary concrete, and also more durable concrete for salty water effects by using ceramic.

Mechanical Properties of Modified Polypropylene Coarse Fiber-Reinforced, High-Strength, Lightweight Concrete

2011 ◽  
Vol 374-377 ◽  
pp. 1499-1506
Author(s):  
Rong Hui Zhang ◽  
Jian Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
High Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume

In this study, the effect of micro-expansion high strength grouting material (EGM) and Modified polypropylene coarse fiber (M-PP fiber) on the mechanical properties of lightweight concrete are investigated. The influence of EGM and M-PP fiber on compressive strength , flexural strength and drying shrinkage of concrete are researched, and flexural fracture toughness are calculated. Test results show that the effect of EGM and M-PP fiber volume fraction (Vf) on flexural strength and fracture toughness is extremely prominent, compressive strength is only slightly enhanced, and the rate of shrinkage is obviously decreased. It is observed that the shape of the descending branch of load-deflection and the ascending branch of shrinkage-age tends towards gently with the increase of Vf. And M-PP fiber reinforced lightweight aggregate concrete is more economical.

scholarly journals Effects of Different Storage Conditions on Mechanical Properties of CAD/CAM Restorative Materials

2019 ◽  
pp. 161-174
Author(s):  
Ayşe Atay DDS, PhD ◽  
Elçin Sağirkaya DDS, PhD
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Flexural Modulus ◽  
Water Storage ◽  
Storage Conditions ◽  
Flexural Test ◽  
Cad Cam ◽  
Provisional Restoration ◽  
Hardness Values

The aim of this study was to evaluate mechanical properties of six new-generation all-ceramic materials for CAD/CAM (Lava Ultimate [LU], VITA Mark II [VM], InCoris TZI [IC], IPS e.max CAD [EM], VITA Suprinity [VS], IPS Empress CAD [EC]) and two different provisional restoration CAD/CAM materials (Telio CAD [TC], Vita CAD-Temp [VC]) after different storage conditions. 36 bar-shaped samples of 4 mm in width and 14 mm in length with 1.2 mm thicknesses were prepared from each material group (N=288). The specimens from each material were kept under three different storage conditions (n=12): under dry conditions at room temperature; 37°C distilled water for 7 days; and 37°C distilled water for 7 days followed by 10,000 thermal cycles. All specimens were subjected to a 3-point flexural test with a crosshead speed of 1.0 mm/min. The specimens were loaded until failure. Twelve fractured specimens after the flexural test from each group were used for the Vickers hardness test (under 300 gf of loading in 15 seconds). The flexural modulus, flexural strength and Vickers hardness values were separately analyzed with two-way analysis of variance, Tukey’s multiple comparison tests at a significance level of p<0.05. There were statistically significant differences between materials and storage conditions according to flexural modulus, flexural strength and Vickers hardness values (p<0.05).  The flexural strength, flexural modulus and Vickers hardness values of LU, VC, TC, VS and IC decreased after water storage followed by thermal cycling (p<0.05). The mechanical properties of provisional restoration CAD/CAM materials had showed a significantly decrease after water storage followed by thermal cycles but their mechanical properties were acceptable for fabrication of provisional restorations. The mechanical properties of VM, EC and EM were not affected by different storage conditions whereas IC and VS were affected.

scholarly journals Behaviour of Self-Compacting Concrete incorporating Natural Perlite used as Part of Cement and as Aggregates

2021 ◽  
Vol 16 (2) ◽  
pp. 115-132
Author(s):  
Sabria Malika Mansour ◽  
Youcef Ghernouti
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Natural Resources ◽  
Environmental Pollution ◽  
Cementitious Material ◽  
Self Compacting Concrete ◽  
Supplementary Cementitious Material ◽  
Consumption Cost ◽  
Natural Aggregates

Abstract Perlite, a natural glassy volcanic rock could be used as supplementary cementitious material to reduce environmental pollution and the consumption of precious natural resources in the concrete industries. The aim of this work is to assess natural perlite used as 50% aggregates substitution by volume (sand or gravel) and as 10%, 15%, 20% cement substitution in self-compacting concrete. Workability characteristics and mechanical properties were analysed. Results showed that replacing 50% of natural aggregates with 50% of perlite aggregates or substituting cement with 10% of perlite powder generated the best workability characteristics and improved compressive, flexural strength, and elastic modulus of concrete at 28 days. Moreover, the results were combined to develop correlations that prove to be good between mechanical properties of self-compacting. Using perlite as aggregates offers a new source of supply and saves natural aggregates. Also, perlite used as cement substitution helps to reduce PC consumption, cost, and CO2 emission.

Strength of Concrete with Recycled Manganese Slag

2021 ◽  
Vol 1030 ◽  
pp. 88-93
Author(s):  
Adeline Ling Ying Ng ◽  
Hock Rui Liew ◽  
Yew Ching Wong
Keyword(s):  
Flexural Strength ◽  
Coarse Aggregate ◽  
Concrete Strength ◽  
Control Sample ◽  
Strength Test ◽  
Control Specimen ◽  
Test Results ◽  
Coarse Aggregates ◽  
Maximum Compressive Strength ◽  
Manganese Slag

This paper studies the effect of replacing coarse aggregates with manganese slag on the mechanical properties of concrete. Air-cooled granulated manganese slag was used. The control sample was designed to achieve concrete strength of 30 MPa at 28 days. Tests were conducted on five different compositions of concrete having manganese slag to coarse aggregates ratios of 0, 0.2, 0.3, 0.4, and 1. The specimens were tested at 7, 14, and 28 days for their compressive and flexural strength. Test results revealed that all manganese slag concrete specimens had improved compressive and flexural strength. The maximum compressive strength achieved was 43.54 MPa, increased by 16% of the control specimen and the maximum flexural strength achieved was 4.50 MPa, increased by 22% of the control specimen. Both results were obtained in concrete with 0.4 manganese slag to coarse aggregate ratio. Besides, the study also showed that it might be possible to substitute all coarse aggregates in concrete with manganese slag without any loss in strength. However, it was observed that the concrete workability decreased when manganese slag was added. Nonetheless, this could be corrected using superplasticizer.

The Effect of Blending Ratio on Mechanical Properties of Polylactic Acid (PLA) / Ethylene Vinyl Acetate (EVA)

2014 ◽  
Vol 554 ◽  
pp. 194-198
Author(s):  
Abdul Manan Siti Najihah ◽  
Zurina Mohamad
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Polylactic Acid ◽  
Vinyl Acetate ◽  
Flexural Modulus ◽  
Ethylene Vinyl Acetate ◽  
Flexural Test ◽  
Screw Extruder ◽  
Blend Ratio ◽  
Twin Screw

The objective of the study is to improve the mechanical properties of Polylactic acid (PLA)/Ethylene Vinyl Acetate (EVA) blend. The blend was prepared via twin screw extruder and compression molding with different composition. The effect of different blend ratio on the mechanical properties was investigated by Tensile and Flexural test. The mechanical properties of PLA shown an improvement compared to the pure PLA with the incorporation of EVA. The flexural modulus increased with the increased of EVA content, while the tensile and flexural strength also increased when EVA increased. The optimum tensile and flexural strength was at 90PLA/10EVA of blends ratio.

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