Recycled Concrete Using Crushed Construction Waste Bricks Subject to Elevated Temperatures

2010 ◽  
Vol 152-153 ◽  
pp. 1-10
Author(s):  
Chung Ming Ho ◽  
Wei Tsung Tsai
Keyword(s):  
Compressive Strength ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
Plain Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Recycled Concrete ◽  
Fine Aggregate ◽  
Term Performance

The objectives of this paper are to find the compressive strength and ultrasonic pulse velocity (UPV) of recycled concrete with various percentages of natural fine aggregate replaced by Recycled brick fine aggregate (RBFA) as well as the residual strength and residual UPV of recycled concrete subjected to elevated temperatures. Experiment results showed that the compressive strength and UPV decreased as amount of RBFA in concrete increased, the long-term performance of compressive strength and UPV development increased as the RBFA content increased. The residual strength of recycled concrete increased slightly after heating to 300°C and the residual UPV of recycled concrete decreased gradually as the exposed temperature increased beyond 300°C. In the range of 580 -800°C, recycled concrete lost most of its original compressive strength and UPV. After subjected to the temperature of 800°C, compared to plain concrete, recycled concrete with 100% RBFA had a greater discount rate of compressive strength and UPV of the order of 5-15% and 6-10%. Regression analysis results revealed that the residual strength and residual UPV of recycled concrete had a high relevance after elevated temperatures exposure.

Effect of Elevated Temperature on the Strength and Ultrasonic Pulse Velocity of Glass Fiber and Nano-Clay Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 1532-1539 ◽  
Author(s):  
Chung Ming Ho ◽  
Wei Tsung Tsai
Keyword(s):  
Compressive Strength ◽  
Glass Fiber ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Nano Clay ◽  
Compressive Strength Of Concrete ◽  
Temperature Exposure

The objectives of this paper are to find the strength and ultrasonic pulse velocity (UPV) of concrete adding admixtures by glass fiber and nano-clay. Residual strength and residual UPV of concrete specimens subjected to elevated temperatures are investigated. Experiment results showed that adding glass fiber and nano-clay would be beneficial for the later-age compressive strength of concrete. Adding nano-clay could considerably increase the flexural and split strength and the toughness of concrete. It is revealed that adding nano-clay could significantly maintain residual compressive and split strength of specimens after high temperature exposure. Regression analysis results revealed that the residual strength and residual UPV of concrete specimens had a high relevance after elevated temperatures exposure.

scholarly journals Empirical Formula for Assessment Concrete Compressive Strength by Using Ultrasonic Pulse Velocity

2018 ◽  
Vol 7 (4.20) ◽  
pp. 113
Author(s):  
Hameed Shakir Al-Aasm
Keyword(s):  
Compressive Strength ◽  
Empirical Formula ◽  
Salt Content ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Fine Aggregate ◽  
Acceptable Error ◽  
Statistical Program ◽  
Compressive Strength Of Concrete

Statistical practical program was carried out to establish a fairly accurate empirical formula between compressive strength of concrete and ultrasonic pulse velocity. The work has a strong empirical base, but it is firmly governed by theory. In concrete, the compressive strength of concrete is related to the type, proportion and physical properties of aggregate but it is well known to be intensely affected by the properties of the cement paste, which relate, mainly, to the w/c ratio. The other variables such as age and density of concrete, salt content in fine aggregate and curing method have a relatively little effect on compressive strength of concrete. Therefore, the program involves field testing of reinforced concrete members that their w/c ratio and cube uniaxial compressive strength are known. The results were used as input data in statistical program (SPSS) to develop an empirical formula between the compressive strength of concrete and ultrasonic pulse velocity. The proposed formula was confirmed by the results of previous experiments. Although the relationship between the compressive strength of concrete and ultrasonic pulse velocity physically indirect, the statistical program revealed that the pulse velocity test could be used with acceptable error in evaluating the compressive strength of concrete.  

scholarly journals Physical and Mechanical Characteristics of Sustainable Concrete Comprising Industrial Waste Materials as a Replacement of Conventional Aggregate

2021 ◽  
Vol 13 (8) ◽  
pp. 4306
Author(s):  
Fadi Althoey ◽  
Md. Akter Hosen
Keyword(s):  
Compressive Strength ◽  
Mechanical Characteristics ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Waste Materials ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Conventional Concrete ◽  
Sustainable Concrete

In a sustainable approach, it is essential to reduce waste materials for improving the urban environmental performance leads to development in the livable, sustainable, and greener city. In pursuit of this goal, iron lathe waste was used in this study as a replacement of fine aggregate to produce sustainable concrete. Iron lathe waste is generally a waste material from the lathe machine, which is abundantly available to an extent. These waste materials may lead to environmental and health concerns. Therefore, the main goal of this study is to experimentally examine the physio-mechanical characteristics of sustainable concrete incorporating lathe iron waste. The lathe iron waste dusts (LIWD) were used as a partial replacement of fine aggregate in different levels by weight (5%, 10%, 15%, and 20%) to fabricate the sustainable concrete. The mechanical and physical properties of sustainable concrete were investigated by conducting tests, such as workability, ultrasonic pulse velocity, compressive strength, splitting tensile strength, and flexural strength to investigate the properties of the alternative concrete comparing with that of conventional concrete. The experimental results showed that the LIWD significantly enhanced the tensile, flexural, and compressive strength of the concrete up to 13%, 19%, and 38%, respectively. Therefore, LIWD can potentially improve the serviceability of the structural elements.

scholarly journals Evaluation of residual strength with ultrasonic pulse velocity relationship for concrete exposed to high temperatures

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110349
Author(s):  
Yeol Choi ◽  
Joo-Won Kang ◽  
Tae-Yeon Hwang ◽  
Chang-Geun Cho
Keyword(s):  
Compressive Strength ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Linear Equations ◽  
Ultrasonic Pulse Velocity ◽  
Tensile Tests ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Velocity Relationship ◽  
The Difference

This paper presents the results of an experimental investigation on the relationship between strength and ultrasonic pulse velocity (UPV) of concrete exposed to high temperature, especially for a decision of building remodeling of concrete structures. The experiments were conducted at three different initial compressive strength levels for temperature up to 800°C. UPV, Compressive, and splitting tensile tests and UPV measurements were performed for unheated and heated concrete specimens. The measured UPV values in the present work were correlated with compressive and tensile strengths to estimate the strength of concrete. Based on the results, two linear equations for predicting compressive and tensile strength of concrete at elevated temperatures using UPV have been proposed. It is found that the difference of initial compressive strength of concrete does not have a significant effect on the strength reduction ratio after exposed to high temperatures. In addition, the reduction factors of compressive and tensile strengths in the present work do not well comply with the values of suggested by EN 1992-1-2.

PENGKAJIAN KEKUATAN BETON STRUKTUR JEMBATAN PASCA KEBAKARAN

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Strength Assessment ◽  
Concrete Testing

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.

scholarly journals The Hydration, Mechanical, Autogenous Shrinkage, Durability, and Sustainability Properties of Cement–Limestone–Slag Ternary Composites

2021 ◽  
Vol 13 (4) ◽  
pp. 1881
Author(s):  
Mei-Yu Xuan ◽  
Yi Han ◽  
Xiao-Yong Wang
Keyword(s):  
Compressive Strength ◽  
Electrical Resistivity ◽  
Experimental Studies ◽  
Autogenous Shrinkage ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Hydration Heat ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio

This study examines the hydration–mechanical–autogenous shrinkage–durability–sustainability properties of ternary composites with limestone filler (LF) and ground-granulated blast furnace slag (BFS). Four mixtures were prepared with a water/binder ratio of 0.3 and different replacement ratios varying from 0 to 45%. Multiple experimental studies were performed at various ages. The experimental results are summarized as follows: (1) As the replacement levels increased, compressive strength and autogenous shrinkage (AS) decreased, and this relationship was linear. (2) As the replacement levels increased, cumulative hydration heat decreased. At the age of 3 and 7 days, there was a linear relationship between compressive strength and cumulative hydration heat. (3) Out of all mixtures, the ultrasonic pulse velocity (UPV) and electrical resistivity exhibited a rapid increase in the early stages and tended to slow down in the latter stages. There was a crossover of UPV among various specimens. In the later stages, the electrical resistivity of ternary composite specimens was higher than plain specimens. (4) X-ray diffraction (XRD) results showed that LF and BFS have a synergistic effect. (5) With increasing replacement ratios, the CO2 emissions per unit strength reduced, indicating the sustainability of ternary composites.

Estimation of Compressive Strength of Recycled Aggregate High Strength Concrete Using Ultrasonic Pulse Velocity

2014 ◽  
Vol 605 ◽  
pp. 147-150
Author(s):  
Seong Uk Hong ◽  
Seung Hun Kim ◽  
Yong Taeg Lee
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Recycled Aggregate ◽  
Strength Concrete ◽  
Recycled Coarse Aggregate

This study used the ultrasonic pulse velocity method, one of the non-destructive test methods that does not damage the building for maintenance of to-be-constructed concrete structures using recycled aggregates in order to estimate the compressive strength of high strength concrete structure using recycled coarse aggregate and provide elementary resources for technological establishment of ultrasonic pulse velocity method. 200 test pieces of high strength concrete 40, 50MPa using recycled coarse aggregate were manufactured by replacement rates (0, 30, 50, 100%) and age (1, 7, 28, 180days), and air curing was executed to measure compressive strength and wave velocity. As the result of compressive strength measurement, the one with age of 180day and design strength of 40MPa was 43.69MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 42.82, 41.22, 37.35MPa, and 50MPa was 52.50MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 49.02, 46.66, 45.30MPa, and while it could be seen that the test piece substituted with recycled aggregate was found to have lower strength than the test piece with natural aggregate only, but it still reached the design strength to a degree. The correlation of compressive strength and ultrasonic pulse velocity was found and regression analysis was conducted. The estimation formula for compressive strength of high strength concrete using recycled coarse aggregate was found to be Fc=0.069Vp4.05, R2=0.66

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