scholarly journals Coconut Fiber Strengthen High Performance Concrete: Young’s Modulus, Ultrasonic Pulse Velocity and Ductility Properties

2018 ◽  
Vol 7 (2.23) ◽  
pp. 284 ◽  
Author(s):  
M A. Othuman Mydin ◽  
N Mohd Zamzani
Keyword(s):  
Young’S Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Young's Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Engineering Properties ◽  
Axial Compressive Strength ◽  
Coconut Fibre

This paper emphasis on experimental investigation to govern the engineering properties such as young’s modulus, pundit ultrasonic pulse velocity (UPV) and ductility of High Performance Concrete (HPC) with grade M60 with addition of coconut fibre (CNF) together with silica fume (SF) and pulverised fuel ash (PFA). For this study, 3 mixes were prepared. First was the CNFRC without any additives, secondly the CNFRC made by 10% replacement of cement weight with PFA and thirdly composition of 10% of cement weight was exchanged with SF. It should be pointed out that for each mix; CNF was included in the mixture (0.5% of the mix volume). The investigational results had shown that the Young’s modulus of CNFRC, CNFR SFC and CNFR PFAC enhanced by about 6%, 3%, and 12% correspondingly. In terms of ductility, when control HPC specimens were subjected to axial compressive strength, slight preliminary cracks shaped on the surface of specimens. Among all HPC specimens tested, CNFR PFAC attained the utmost UPV at 28 day.    

scholarly journals Transport Properties and Resistance Improvement of Ultra-High Performance Concrete (UHPC) after Exposure to Elevated Temperatures

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 416
Author(s):  
Yunfeng Qian ◽  
Dingyi Yang ◽  
Yanghao Xia ◽  
Han Gao ◽  
Zhiming Ma
Keyword(s):  
Compressive Strength ◽  
Transport Properties ◽  
High Temperatures ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Capillary Absorption ◽  
Self Healing

Ultra-high performance concrete (UHPC) has a high self-healing capacity and is prone to bursting after exposure to high temperatures due to its characteristics. This work evaluates the damage and improvement of UHPC with coarse aggregates through mechanical properties (compressive strength and ultrasonic pulse velocity), transport properties (water absorption and a chloride diffusion test), and micro-properties such as X-ray diffraction (XRD), Mercury intrusion porosimetry (MIP), and Scanning electronic microscopy (SEM). The result demonstrates that polypropylene (PP) fibers are more suitable for high temperature tests than polyacrylonitrile (PAN) fibers. The result shows that 400 °C is the critical temperature point. With the increase in temperature, the hydration becomes significant, and the internal material phase changes accordingly. Although the total pore volume increased, the percentage of various types of pores was optimized within 400 °C. The mass loss gradually increased and the ultrasonic pulse velocity gradually decreased. While the compressive strength first increased and then decreased, and the increase occurred within 25–400 °C. As for the transport properties, the chloride migration coefficient and capillary absorption coefficient both increased dramatically due to the higher sensitivity to temperature changes. The results of the property improvement test showed that at temperatures above 800 °C, the compressive strength recovered by more than 65% and the ultrasonic pulse velocity recovered by more than 75%. In terms of transport properties, compared to the results before self-healing, the chloride migration coefficient decreased by up to 59%, compared with 89% for the capillary absorption coefficient, after self-healing at 800 °C. With respect to the enhancement effect after exposure to high temperatures, the environment of a 5% Na2SO4 solution was not as good as the clean water environment. The corresponding changes in microstructure during the high temperatures and the self-healing process can explain the change in the pattern of macroscopic properties more precisely.

The Combined Effect of CKD and Silica Fume on the Mechanical and Durability Performance of Cement Mortar

2021 ◽  
Vol 895 ◽  
pp. 59-67
Author(s):  
Mayadah W. Falah ◽  
Alaa Adnan Hafedh ◽  
Safa A. Hussein ◽  
Zainab S. Al-Khafaji ◽  
Ali A. Shubbar ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cement Kiln ◽  
Substitute Products

To manufacture high-strength and high-performance concrete, the incorporation of silica fume with concrete was becoming popular nowadays. When utilizing various amounts of cement substitute products, the design becomes even more complicated. The latest research has been dedicated to researching the applicability of cement substitute products for cement kiln dust (CKD) and silica fume (SF). In permeability and compressive strength terms, the effect of these components on the efficacy of the concrete would be studied. Also, the materials proposed might limit greenhouse gas emissions, which will mitigate climate change on other causes of global pollution. Casting a standard concrete cube (100 percent OPC) equivalent to (150 gm) would initiate the experiment, which was utilized later for comparative purposes. The industrial waste materials (SF and CKD) was be applied as cement substitution proportions (10 percent, 20 percent, and 30 percent) of the dry cement weight at varying percentages of each component (5 percent, 10 percent, and 15 percent). Eventually, after 7, 14, 28 days, the compressive strength shift would be calculated. The permeability of the latest concrete will be checked after (7, 14, and 28) days of healing utilizing ultrasonic pulse velocity (UPV) technology. The experimental findings indicate that with a specimen comprising 20 percent of (SF and CKD) relative to (100 percent OPC) specimen, there is an improvement in compressive intensity and pulse velocity values in various curing times and specimens of various (SF and CKD) specimen M3 have a decrease in pulse velocity value after 7 curing days.

Examining the Influence of the Shape, Size, and Type of Test Specimens on the Value of Young's Modulus in Lightweight Concrete

2019 ◽  
Vol 292 ◽  
pp. 29-33
Author(s):  
Dalibor Kocáb ◽  
Petr Daněk ◽  
Petr Žítt ◽  
Aleš Tichý ◽  
Martin Alexa
Keyword(s):  
Elastic Modulus ◽  
Statistical Analysis ◽  
Young’S Modulus ◽  
Dynamic Modulus ◽  
Lightweight Concrete ◽  
Young's Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity

The paper discusses the results of an experiment that focused on measuring Young's modulus in compression using several different specimens. They were made from lightweight concrete with porous aggregate and differed in shape (cylinder × prism), type (casting × core drilling), and size. Each type category counted a minimum of 6 specimens. The determination of Young's modulus was supplemented by a measurement of the dynamic modulus of elasticity determined by the ultrasonic pulse velocity test. The experiment was concluded by a statistical analysis of the measured values, which focused on the influence of each specimen variety on the value of the elastic modulus.

The Effect of Different Sand Gradation with Ultra High Performance Concrete (UHPC)

2018 ◽  
Vol 280 ◽  
pp. 476-480 ◽  
Author(s):  
N.A. Hamiruddin ◽  
R. Abd Razak ◽  
K. Muhamad ◽  
M.Z.A. Mohd Zahid ◽  
C.N.S. Che Ab Aziz
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Material Research ◽  
Ultra High Performance Concrete ◽  
New Class ◽  
Flow Test

Advances in concrete material research has introduced to development the new class of concrete which is known as Ultra High Performance Concrete (UHPC). Due to the most exceedingly awful on nature coarse aggregate quality, UHPC was delivered to success in concrete. This study investigated the effect of differentsand gradation (63-300μm, 300-600μm, 600-1180μm, and normal sand) on compressive strength and ultrasonic pulse velocity (UPV) of UHPC. The rheology of UHPC mixtures was determined by flow test conducted according to ASTM C1611 and the compression testwas performed to measure concrete compression strength at 7 and 28 days according to BS 1881-116 (1983). To determine the quality of concrete, UPV test were conducted according to BS 1881 part 201 (1986).From the experimental results, the results indicated that sand grading with 600-1180μm obtained the highest in compressive strength and UPV.The compressive strength at 28 days achieved 100 MPawith direct transmission of UPV 4.5% higher than semi direct.

scholarly journals Mechanical Properties and Environmental Evaluation of Ultra-High-Performance Concrete with Aeolian Sand

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3148 ◽  
Author(s):  
Hongyan Chu ◽  
Fengjuan Wang ◽  
Liguo Wang ◽  
Taotao Feng ◽  
Danqian Wang
Keyword(s):  
Compressive Strength ◽  
Environmental Impact ◽  
Young’S Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Young's Modulus ◽  
Ultra High Performance Concrete ◽  
Aeolian Sand ◽  
Binder Ratio ◽  
Water Binder Ratio

Ultra-high-performance concrete (UHPC) has received increasing attention in recent years due to its remarkable ductility, durability, and mechanical properties. However, the manufacture of UHPC can cause serious environmental issues. This work addresses the feasibility of using aeolian sand to produce UHPC, and the mix design, environmental impact, and mechanical characterization of UHPC are investigated. We designed the mix proportions of the UHPC according to the modified Andreasen and Andersen particle packing model. We studied the workability, microstructure, porosity, mechanical performance, and environmental impact of UHPC with three different water/binder ratios. The following findings were noted: (1) the compressive strength, flexural strength, and Young’s modulus of the designed UHPC samples were in the ranges of 163.9–207.0 MPa, 18.0–32.2 MPa, and 49.3–58.9 GPa, respectively; (2) the compressive strength, flexural strength, and Young’s modulus of the UHPC increased with a decrease in water/binder ratio and an increase in the steel fibre content; (3) the compressive strength–Young’s modulus correlation of the UHPC could be described by an exponential formula; (4) the environmental impact of UHPC can be improved by decreasing its water/binder ratio. These findings suggest that it is possible to use aeolian sand to manufacture UHPC, and this study promotes the application of aeolian sand for this purpose.

Recycling of Waste Limestone as Fine Aggregate for Conventional and Green Concretes

2018 ◽  
Vol 928 ◽  
pp. 257-262 ◽  
Author(s):  
Trong Phuoc Huynh ◽  
Chao Lung Hwang ◽  
Si Huy Ngo
Keyword(s):  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Concrete Mixture ◽  
Engineering Properties ◽  
Fine Aggregate ◽  
Normal Concrete ◽  
Design Algorithm ◽  
Green Concrete ◽  
Concrete Mixtures

This paper presents the results of the experimental works to investigate the use of waste limestone from water treatment industry as fine aggregate in green concrete. Two concrete mixtures with a constant water-to-binder ratio of 0.3 were prepared for this investigation, in which, the normal concrete mixture was designed following the guidelines of ACI 211 standard, while the green concrete mixture was designed using densified mixture design algorithm (DMDA) technology. For comparison, both types of concrete samples were subjected to the same test program, including fresh properties, compressive strength, strength efficiency of cement, drying shrinkage, electrical surface resistivity, ultrasonic pulse velocity, and thermal conductivity. Test results indicate that both concrete mixtures showed the excellent workability due to the round-shape of waste limestone aggregate and the use of superplasticizer. In addition, the green concrete mixture exhibited a better performance in terms of engineering properties and durability in comparison with the normal concrete mixture. The results of the present study further support the recycling and reuse of waste limestone as fine aggregate in the production of green concrete.

Strength - Ultrasonic Pulse Velocity Relationship of Thermally Activated Alum Sludge Multiple Blended High Performance Concretes

2013 ◽  
Vol 594-595 ◽  
pp. 521-526 ◽  
Author(s):  
Haider Mohammed Owaid ◽  
Roszilah Hamid ◽  
Mohd Raihan Taha
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Ternary Blends ◽  
Exponential Relationship ◽  
Palm Oil Fuel Ash ◽  
Thermally Activated ◽  
Alum Sludge

In this research the performance of ultrasonic pulse velocity in concrete is examined as a nondestructive experiment, in order to estimate compressive strength of thermally activated alum sludge multiple blended high performance concretes (HPC) that contain AAS, silica fume (SF), ground granulated blast furnace slag (GGBS) and palm oil fuel ash (POFA) are determined in both binary and ternary blends of cement. The water/binder ratio and total binder content are fixed at 0.30 and 493 kg/m3 for all types of mixes. The ultrasonic pulse velocity (UPV) of each concrete mix was measured using 100mm cubes after a curing period of ages of 3, 7, 28, 56 and 90 days. The results indicate a very positive exponential relationship between compressive strength and UPV for both binary and ternary blends of HPC mixtures, with coefficient correlation (R2) of 0.889.

scholarly journals Prediction of the compressive strength of high-performance self-compacting concrete by an ultrasonic-rebound method based on a GA-BP neural network

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250795
Author(s):  
Guoqiang Du ◽  
Liangtao Bu ◽  
Qi Hou ◽  
Jing Zhou ◽  
Beixin Lu
Keyword(s):  
Neural Network ◽  
Compressive Strength ◽  
Correlation Coefficient ◽  
High Performance ◽  
Ultrasonic Pulse Velocity ◽  
Test Sample ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Self Compacting Concrete ◽  
Bpnn Model

To address the problem of low accuracy and poor robustness of in situ testing of the compressive strength of high-performance self-compacting concrete (SCC), a genetic algorithm (GA)-optimized backpropagation neural network (BPNN) model was established to predict the compressive strength of SCC. Experiments based on two concrete nondestructive testing methods, i.e., ultrasonic pulse velocity and Schmidt rebound hammer, were designed and test sample data were obtained. A neural network topology with two input nodes, 19 hidden nodes, and one output node was constructed, and the initial weights and thresholds of the resulting traditional BPNN model were optimized using GA. The results showed a correlation coefficient of 0.967 between the values predicted by the established BPNN model and the test values, with an RMSE of 3.703, compared to a correlation coefficient of 0.979 between the values predicted by the GA-optimized BPNN model and the test values, with an RMSE of 2.972. The excellent agreement between the predicted and test values demonstrates the model can accurately predict the compressive strength of SCC and hence reduce the cost and time for SCC compressive strength testing.

Mechanics-based algorithms to determine the current state of a bridge using quasi-static loading and strain measurement

2018 ◽  
Vol 18 (5-6) ◽  
pp. 1874-1888 ◽  
Author(s):  
Pandi Pitchai ◽  
U Saravanan ◽  
Rupen Goswami
Keyword(s):  
Boundary Conditions ◽  
Young’S Modulus ◽  
Material Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Young's Modulus ◽  
Moving Load ◽  
Material Parameters ◽  
Current State ◽  
Slow Moving

Knowing the current state of a bridge is of interest for a variety of reasons. Some parameters that determine the current state of a bridge are the material properties and boundary conditions. Using strain measurements obtained from a slow-moving vehicle on a bridge, the boundary condition and material properties are determined through a mechanistic-based approach. Observing that the sign of the curvature would change at locations near the support when a load passes over a bridge with end rotational restraints, a methodology for determining the boundary conditions is proposed and validated. The linear elastic properties of the material that the bridge is made up of is determined from the strain measured at locations where the stress is independent of the material property. In this procedure, the structure is analyzed assuming some material properties and the stress at the measured point is determined. Then, the material parameters in the isotropic Hooke’s law are determined so that the stress estimated from the experimentally determined strains agrees with that obtained from the analysis with arbitrarily assumed material parameters. A prestressed high-performance concrete pi-shaped girder tested under a three-axle slow-moving load with strains measured at different locations is used to bring out the efficacy and appropriateness of the proposed methodologies. The mean value of Young’s modulus of the prestressed concrete bridge agrees well with the experimentally determined Young’s modulus.

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