Size Effect of Waste Compact Disc Shred on Properties of Concrete

2011 ◽  
Vol 346 ◽  
pp. 40-46 ◽  
Author(s):  
Wai Ching Tang ◽  
Yiu Lo ◽  
Hong Zhi Cui
Keyword(s):  
Size Effect ◽  
Fracture Energy ◽  
Volume Fraction ◽  
Characteristic Length ◽  
Strength Properties ◽  
Compact Disc ◽  
Beam Test ◽  
Cracking Resistance ◽  
Three Point Bending ◽  
Concrete Properties

In this research, the mechanical and fracture behaviours of concrete containing waste CD shreds were investigated using the three-point bending notched beam test, according to RILEM recommendations. The size effect of waste CD shred on concrete properties was the focus of this research. The study indicates that the fracture energy and modified characteristic length were found to increase significantly with increasing the size and volume fraction of CD shreds due to anchoring and bridging effects. In other words, concrete with higher amounts and larger sizes of CD shreds exhibit higher cracking resistance and the brittleness decreases accordingly. However, the strength properties were found to decrease when concrete with larger portion and size of CD shreds.

Fracture properties of GGBS-dolomite geopolymer concrete

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saranya P. ◽  
Praveen Nagarajan ◽  
A.P. Shashikala
Keyword(s):  
Fracture Energy ◽  
Design Methodology ◽  
Characteristic Length ◽  
Peak Load ◽  
Critical Stress Intensity Factor ◽  
Bending Test ◽  
Geopolymer Concrete ◽  
Content Type ◽  
Fracture Properties ◽  
Three Point Bending

Purpose This study aims to predict the fracture properties of geopolymer concrete, which is necessary for studying failure behaviour of concrete. Design/methodology/approach Geopolymers are new alternative binders for cement in which polymerization gives strength to concrete rather than through hydration. Geopolymer concrete was developed from industrial byproducts such as GGBS and dolomite. Present study estimates the fracture energy of GGBS geopolymer concrete using three point bending test (RILEM TC50-FMC) with different percentages of dolomite and compare with cement concrete having same strength. Findings The fracture properties such as peak load, critical stress intensity factor, fracture energy and characteristic length are found to be higher for GGBS-dolomite geopolymer concrete, when their proportion becomes 70:30. Originality/value To the best of the authors’ knowledge, this is an original experimental work.

scholarly journals Effect of Palm Oil Fiber (POF) to Strength Properties and Fracture Energy of Green Concrete

2018 ◽  
Vol 79 (1) ◽  
Author(s):  
Abdul Aziz Abdul Samad ◽  
Cindy Wong Yean Theng ◽  
Tim Ee Ching ◽  
Noridah Mohamad ◽  
Muhammad Afiq Tambichik ◽  
...  
Keyword(s):  
Fracture Energy ◽  
Palm Oil ◽  
Strength Properties ◽  
Strength Test ◽  
Recycled Concrete ◽  
Bending Test ◽  
Concrete Aggregate ◽  
Palm Oil Fuel Ash ◽  
Green Concrete ◽  
Three Point Bending

The lack of research on concrete which utilizes Palm Oil Fuel Ash (POFA), Rice Husk Ash (RHA), Recycled Concrete Aggregate (RCA) and Palm Oil Fiber (POF) simultaneously in concrete was globally observed. To meet this gap, a study on green concrete consisting of POFA, RHA and RCA with added untreated POF as binders was conducted. The study focusses on the effect of varying percentages of untreated POF, ranging from 0%, 0.25%, 0.50% and 0.75%, to the strength properties and fracture energy of green concrete. The strength properties of green concrete were investigated by conducting the compression strength test and tensile strength test on forty-eight (48) cubes and cylinders at the curing age of 7 and 28 days. The tests show that the strength of green concrete decreases, as the percentage of POF increases. This was preceded by the establishment of an optimum percentage of POF at 0.25%. The fracture energy of the green concrete was determined by testing twelve numbers of notched beams with dimensions of 100mm x 100mm x 500mm under the three-point bending test. From the three-point bending test, the load-deflection profile for each specimen with different percentages of untreated POF was obtained. Three existing theoretical models, namely Hillerborg, Bazant and CEB models were used to measure the fracture energy of the green concrete with varying percentage of fiber. Results range from 37.94 N/m to 153.81 N/m was observed. The study also successfully established the reliability of Hillerborg’s model to fracture energy when models by Bazant and CEB surprisingly shows a decrease in fracture energy measurements with increase in fiber content.

scholarly journals Performance Evaluation of Soft Computing for Modeling the Strength Properties of Waste Substitute Green Concrete

2021 ◽  
Vol 13 (5) ◽  
pp. 2867
Author(s):  
Muhammad Izhar Shah ◽  
Muhammad Nasir Amin ◽  
Kaffayatullah Khan ◽  
Muhammad Sohaib Khan Niazi ◽  
Fahid Aslam ◽  
...  
Keyword(s):  
Predictive Models ◽  
Parametric Study ◽  
Cross Validation ◽  
Strength Properties ◽  
Fine Aggregate ◽  
Agricultural Industry ◽  
Green Concrete ◽  
Concrete Properties ◽  
Water To Cement Ratio ◽  
Sugarcane Bagasse Ash

The waste disposal crisis and development of various types of concrete simulated by the construction industry has encouraged further research to safely utilize the wastes and develop accurate predictive models for estimation of concrete properties. In the present study, sugarcane bagasse ash (SCBA), a by-product from the agricultural industry, was processed and used in the production of green concrete. An advanced variant of machine learning, i.e., multi expression programming (MEP), was then used to develop predictive models for modeling the mechanical properties of SCBA substitute concrete. The most significant parameters, i.e., water-to-cement ratio, SCBA replacement percentage, amount of cement, and quantity of coarse and fine aggregate, were used as modeling inputs. The MEP models were developed and trained by the data acquired from the literature; furthermore, the modeling outcome was validated through laboratory obtained results. The accuracy of the models was then assessed by statistical criteria. The results revealed a good approximation capacity of the trained MEP models with correlation coefficient above 0.9 and root means squared error (RMSE) value below 3.5 MPa. The results of cross-validation confirmed a generalized outcome and the resolved modeling overfitting. The parametric study has reflected the effect of inputs in the modeling process. Hence, the MEP-based modeling followed by validation with laboratory results, cross-validation, and parametric study could be an effective approach for accurate modeling of the concrete properties.

scholarly journals Comparative study of elastic properties and mode I fracture energy of carbon nanotube/epoxy and carbon fibre/epoxy laminated composites

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jyotikalpa Bora ◽  
Sushen Kirtania
Keyword(s):  
Carbon Nanotube ◽  
Carbon Fibre ◽  
Fracture Energy ◽  
Elastic Properties ◽  
Volume Fraction ◽  
Laminated Composites ◽  
Laminated Composite ◽  
Fe Analysis ◽  
Mode I ◽  
Mode I Fracture

Abstract A comparative study of elastic properties and mode I fracture energy has been presented between conventional carbon fibre (CF)/epoxy and advanced carbon nanotube (CNT)/epoxy laminated composite materials. The volume fraction of CNT fibres has been considered as 15%, 30%, and 60% whereas; the volume fraction of CF has been kept constant at 60%. Three stacking sequences of the laminates viz.[0/0/0/0], [0/90/0/90] and [0/30/–30/90] have been considered in the present analysis. Periodic microstructure model has been used to calculate the elastic properties of the laminated composites. It has been observed analytically that the addition of only 15% CNT in epoxy will give almost the same value of longitudinal Young’s modulus as compared to the addition of 60% CF in epoxy. Finite element (FE) analysis of double cantilever beam specimens made from laminated composite has also been performed. It has been observed from FE analysis that the addition of 15% CNT in epoxy will also give almost the same value of mode I fracture energy as compared to the addition of 60% CF in epoxy. The value of mode I fracture energy for [0/0/0/0] laminated composite is two times higher than the other two types of laminated composites.

scholarly journals Experimental data on strength properties of mussel shell concretes and specimen size effect

Data in Brief ◽  
2021 ◽  
Vol 35 ◽  
pp. 106954
Author(s):  
Costas A. Anagnostopoulos ◽  
Denis Cabja ◽  
Chrysi A. Papadimitriou
Keyword(s):  
Experimental Data ◽  
Size Effect ◽  
Strength Properties ◽  
Specimen Size ◽  
Mussel Shell

scholarly journals Fracture and Size Effect of PFRC Specimens Simulated by Using a Trilinear Softening Diagram: A Predictive Approach

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3795
Author(s):  
Fernando Suárez ◽  
Jaime C. Gálvez ◽  
Marcos G. Alberti ◽  
Alejandro Enfedaque
Keyword(s):  
Reinforced Concrete ◽  
Size Effect ◽  
A Priori ◽  
Plain Concrete ◽  
Specimen Size ◽  
Bending Test ◽  
Orientation Factor ◽  
Fibre Reinforced Concrete ◽  
Softening Function ◽  
Three Point Bending

The size effect on plain concrete specimens is well known and can be correctly captured when performing numerical simulations by using a well characterised softening function. Nevertheless, in the case of polyolefin-fibre-reinforced concrete (PFRC), this is not directly applicable, since using only diagram cannot capture the material behaviour on elements with different sizes due to dependence of the orientation factor of the fibres with the size of the specimen. In previous works, the use of a trilinear softening diagram proved to be very convenient for reproducing fracture of polyolefin-fibre-reinforced concrete elements, but only if it is previously adapted for each specimen size. In this work, a predictive methodology is used to reproduce fracture of polyolefin-fibre-reinforced concrete specimens of different sizes under three-point bending. Fracture is reproduced by means of a well-known embedded cohesive model, with a trilinear softening function that is defined specifically for each specimen size. The fundamental points of these softening functions are defined a priori by using empirical expressions proposed in past works, based on an extensive experimental background. Therefore, the numerical results are obtained in a predictive manner and then compared with a previous experimental campaign in which PFRC notched specimens of different sizes were tested with a three-point bending test setup, showing that this approach properly captures the size effect, although some values of the fundamental points in the trilinear diagram could be defined more accurately.

Experimental and Numerical Investigation of Critical Buckle Load of Composite Specimens

2015 ◽  
Vol 732 ◽  
pp. 85-90
Author(s):  
Lukáš Bek ◽  
Radek Kottner ◽  
Jan Krystek ◽  
Tomáš Kroupa
Keyword(s):  
Static Analysis ◽  
Glass Fibre ◽  
Large Deformations ◽  
Bending Test ◽  
Test Results ◽  
Beam Test ◽  
Three Point Bending ◽  
Box Beams ◽  
Buckle Beam ◽  
Thin Walled

Different carbon and glass fibre strips were subjected to the double clamp buckle beam test. Furthermore, thin-walled glass fibre box-beams were subjected to the three-point bending test. Results of experiments were compared to different numerical simulations using buckling analysis or static analysis considering large deformations.

scholarly journals Simulation of MASPn Experiments in MISTRA Test Facility with COCOSYS Code

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Mantas Povilaitis ◽  
Egidijus Urbonavičius
Keyword(s):  
Boundary Conditions ◽  
Nuclear Power ◽  
Power Plants ◽  
Volume Fraction ◽  
Characteristic Length ◽  
Initial Conditions ◽  
Test Facility ◽  
Work Package ◽  
Acceptable Agreement

An issue of the stratified atmospheres in the containments of nuclear power plants is still unresolved; different experiments are performed in the test facilities like TOSQAN and MISTRA. MASPn experiments belong to the spray benchmark, initiated in the containment atmosphere mixing work package of the SARNET network. The benchmark consisted of MASP0, MASP1 and MASP2 experiments. Only the measured depressurisation rates during MASPn were available for the comparison with calculations. When the analysis was performed, the boundary conditions were not clearly defined therefore most of the attention was concentrated on MASP0 simulation in order to develop the nodalisation scheme and define the initial and boundary conditions. After achieving acceptable agreement with measured depressurisation rate, simulations of MASP1 and MASP2 experiments were performed to check the influence of sprays. The paper presents developed nodalisation scheme of MISTRA for the COCOSYS code and the results of analyses. In the performed analyses, several parameters were considered: initial conditions, loss coefficient of the junctions, initial gradients of temperature and steam volume fraction, and characteristic length of structures. Parametric analysis shows that in the simulation the heat losses through the external walls behind the lower condenser installed in the MISTRA facility determine the long-term depressurisation rate.

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