scholarly journals Physical and mechanical characterization of concrete exposed to elevated temperatures by using ultrasonic pulse velocity

2015 ◽  
Author(s):  
Ricardo Alfredo Cruz-Hernández ◽  
◽  
Luis Eduardo Zapata-Orduz ◽  
Luz Amparo Quintero-Ortiz ◽  
Julián Orlando Herrera-Ortiz ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Mechanical Characterization ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity

Mechanical Characterization of Building Stones through DT and NDT Tests: Research of Correlations for the In Situ Analysis of Ancient Masonry

2014 ◽  
Vol 628 ◽  
pp. 85-89 ◽  
Author(s):  
Emilia Vasanelli ◽  
Maria Sileo ◽  
Giovanni Leucci ◽  
Angela Calia ◽  
Maria Antonietta Aiello ◽  
...  
Keyword(s):  
Mechanical Characterization ◽  
Diagnostic Procedures ◽  
Ultrasonic Pulse Velocity ◽  
Mechanical Analysis ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Reliable Technique ◽  
Non Destructive

In this paper, the use of ultrasonic pulse velocity (UPV) testing as a reliable technique to determine the compressive strength of a calcarenitic stone typical of Salento (South of Italy), known as Lecce Stone (LS) has been investigated. The scope of the experimental research is to establish correlations between the results obtained by non-destructive and destructive tests, in order to reduce the use of destructive methods within the diagnostic procedures for the mechanical analysis and qualification of ancient masonries. Furthermore, the presence of water as a variable affecting the test was investigated. The results of the tests show that the UPV values are well correlated with the compressive strengths and this method showed to be efficient in predicting the strength of LS.

Mechanical Behavior of Gypsum and Cork Based Composite Material

2012 ◽  
Vol 730-732 ◽  
pp. 361-366 ◽  
Author(s):  
Graca Vasconcelos ◽  
Andreia Martins ◽  
Sandra Cunha ◽  
Aires Camões ◽  
Paulo B. Lourenço
Keyword(s):  
Composite Material ◽  
Mechanical Characterization ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Raw Material ◽  
Engineering Construction ◽  
Fgd Gypsum ◽  
By Products

The main aim of this work is the mechanical characterization of a composite material resulting from the combination of three by-products coming from industry, namely, flue gas desulfurization (FGD) gypsum, granulated cork and textile fibers from tire recycling. The material is considered as a green material as the raw material are considered by-products and it is intended to be used as a building material for non-structural purposes in civil engineering construction. The mechanical characterization includes uniaxial compressive tests and bending tests for characterization of the fracture behavior. Additionally, ultrasonic pulse velocity is measured to evaluate its variation with time of curing.

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.

scholarly journals Characterization of pervious concrete focusing on non-destructive testing

2020 ◽  
Vol 13 (3) ◽  
pp. 483-500 ◽  
Author(s):  
S. T. MARTINS FILHO ◽  
E. M. BOSQUESI ◽  
J. R. FABRO ◽  
R. PIERALISI
Keyword(s):  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Pervious Concrete ◽  
Analytical Models ◽  
High Porosity ◽  
Destructive Testing ◽  
Ultrasound Method ◽  
Lower Permeability

Abstract This study aims to investigate the properties of pervious concrete focusing on characterization tests by the Ultrasound Method. For this, three mixtures were produced with the paste/aggregate (P/Ag) ratio ranging from 0.45 to 0.65, water to cement ratio (w/c) of 0.3, and all the specimens were compacted with a steel rod. The application of the ultrasound method deserves special attention for the characterization of pervious concrete, due to a lack of research and the potential to develop analytical models for predicting properties from ultrasonic pulse velocity (UPV) as an independent variable. The UPV obtained in this study ranged from 3642 to 4262 m/s for an approximately 12% reduction in porosity, with a correlation (R²) of 0.91. It is noteworthy that the high porosity of pervious concrete causes attenuation of the ultrasonic wave. The measurements of UPV had higher values for specimens with higher densities (R²=0.87), higher compressive and tensile strengths (R² of 0.79 and 0.84, resp.), and lower permeability (R² = 0.91).

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 MECHANICAL, THERMAL AND DURABLE PERFORMANCE OF WASTES SAWDUST AS COARSE AGGREGATE REPLACEMENT IN CONVENTIONAL CONCRETE

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Gassan Fahim Huseien ◽  
Ruhal Pervez Memon ◽  
Ziyad Kubba ◽  
Abdul Rahaman Mohd Sam ◽  
Mohammad Ali Asaad ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Elevated Temperatures ◽  
Evaluation Process ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Conventional Concrete ◽  
Long Duration ◽  
Mechanical And Physical Properties

Wood yields a number of by-products and Sawdust is as useful as others. Sawdust is regarded as a waste material and is effectively utilised as sawdust concrete in the construction of buildings. It is capable to be utilised as light-weight concrete and holds the quality of long duration heat transfer. In this study, three different ratios (1:1, 1:2 and 1:3) volume mix proportions of cement to sawdust were adopted to make sawdust concrete. At varied intervals of 7, 28 and 56 days of air curing, thermal and mechanical properties like workability, density, elastic modulus, strength and heat transfer were probed of mentioned sawdust concrete proportions. The resistance to elevated temperatures was also evaluated after 28 days of age; weight loss, residual compressive strength, surface texture and ultrasonic pulse velocity were considered in evaluation process. The findings showed that increase in sawdust volume affected to decrease the workability, strength and elevated temperatures resistance. However, the concrete having higher proportion of sawdust performed competently and well in terms of thermal conductivity. Moreover, a decrease in the heat transfer of sawdust was also observed. Examining the all-embracing mechanical and physical properties, sawdust can be effectively utilised in the construction of buildings.

scholarly journals Performance Evaluation of Modified Rubberized Concrete Exposed to Aggressive Environments

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1900
Author(s):  
Akram M. Mhaya ◽  
Mohammad Hajmohammadian Baghban ◽  
Iman Faridmehr ◽  
Ghasan Fahim Huseien ◽  
Ahmad Razin Zainal Abidin ◽  
...  
Keyword(s):  
Building Materials ◽  
Elevated Temperatures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Industrial Applications ◽  
Pulse Velocity ◽  
Rubberized Concrete ◽  
Natural Aggregate ◽  
Artificial Neural Network Ann ◽  
Tire Crumbs

Recycling of the waste rubber tire crumbs (WRTCs) for the concretes production generated renewed interest worldwide. The insertion of such waste as a substitute for the natural aggregates in the concretes is an emergent trend for sustainable development towards building materials. Meanwhile, the enhanced resistance of the concrete structures against aggressive environments is important for durability, cost-saving, and sustainability. In this view, this research evaluated the performance of several modified rubberized concretes by exposing them to aggressive environments i.e., acid, and sulphate attacks, elevated temperatures. These concrete (12 batches) were made by replacing the cement and natural aggregate with an appropriate amount of the granulated blast furnace slag (GBFS) and WRTCs, respectively. The proposed mix designs’ performance was evaluated by several measures, including the residual compressive strength (CS), weight loss, ultrasonic pulse velocity (UPV), microstructures, etc. Besides, by using the available experimental test database, an optimized artificial neural network (ANN) combined with the particle swarm optimization (PSO) was developed to estimate the residual CS of modified rubberized concrete after immersion one year in MgSO4 and H2SO4 solutions. The results indicated that modified rubberized concrete prepared by 5 to 20% WRTCs as a substitute to natural aggregate, provided lower CS and weight lose expose to sulphate and acid attacks compared to control specimen prepared by ordinary Portland cement (OPC). Although the CS were slightly declined at the elevated temperature, these proposed mix designs have a high potential for a wide variety of concrete industrial applications, especially in acid and sulphate risk.

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