Compressive Strength and Flexural Properties of High Performance Nano-Binder Cementitious Composites

2013 ◽  
Vol 275-277 ◽  
pp. 2064-2068 ◽  
Author(s):  
Xiang Gao ◽  
Qing Hua Li ◽  
Shi Lang Xu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
Flexural Properties ◽  
Cementitious Composites ◽  
Nano Sio2 ◽  
The Matrix ◽  
Average Crack ◽  
Sio2 Particles ◽  
Pva Fiber

High performance nano-binder cementitious composites (HPNCC) are ultra-ductile fiber reinforced cementitious composites with special matrix. The compressive strength and flexural properties of HPNCC containing nano-SiO2 particles were investigated at age of 3d, 7d, 14d and 28d. According to the results, HPNCC exhibited excellent mechanical properties in the test. The compressive strength, flexural strength and first crack strain of HPNCC were all increased obviously at early age except the ultimate strain. In the flexural test, both crack extension width and the number of fine cracks decrease along with the curing age. However, the average crack spacing has no remarkable changes. Nano-SiO2 particles in HPNCC acted as ultra-fine fillers and catalyzers to strengthen the interfacial bond between the matrix and PVA fiber which improved the mechanical properties and would make HPNCC be widely used in the engineering.

scholarly journals Mechanical Properties of Hybrid Ultra-High Performance Engineered Cementitous Composites Incorporating Steel and Polyethylene Fibers

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1448 ◽  
Author(s):  
Yingwu Zhou ◽  
Bin Xi ◽  
Kequan Yu ◽  
Lili Sui ◽  
Feng Xing
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
Bending Strength ◽  
Flexural Properties ◽  
Environmental Scanning ◽  
Fiber Volume ◽  
Pseudo Strain Hardening ◽  
Positive Effect ◽  
Opposite Tendency

This paper presents the authors’ newly developed hybrid ultra-high performance (HUHP) engineered cementitious composite (ECC) with steel (ST) and polyethylene (PE) fibers. From this point on it will be referred to as HUHP-ECC. The volumes of steel and PE fibers were adjusted to obtain different mechanical properties, including compressive strength, tensile, and flexural properties. We found that tensile and flexural properties, including bending strength and ductility indexes, increased with higher PE fiber amounts but reduced with the increased ST fiber volume. Notably, the compressive strength had the opposite tendency and decreased with increases in the PE volume. The ST fiber had a significantly positive effect on the compressive strength. The fluidity of HUHP-ECC improved with the increasing amount of ST fiber. The pseudo strain-hardening (PSH) values for all the HUHP-ECC mixtures were used to create an index indicating the ability of strain capacity; thus, the PSH values were calculated to explain the ductility of HUHP-ECC with different fiber volumes. Finally, the morphology of PE and ST fibers at the fracture surface was observed by an environmental scanning electron microscope (ESEM).

Effect of PVA Fiber on Mechanical Properties of High-Performance Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 249-252 ◽  
Author(s):  
Zhe Jin ◽  
Cheng Ya Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Splitting Tensile Strength ◽  
Fiber Volume ◽  
Pva Fiber

An experimental study has been conducted to investigate the effect of the fraction of PVA fiber on the mechanical properties of high-performance concrete. The mechanical properties include compressive strength, splitting tensile strength and compressive elastic modulus. On the basis of the experimental results of the specimens of six sets of mix proportions, the mechanism of PVA fiber acting on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of increase in the compressive strength and splitting tensile strength when the fiber volume fraction is below 0.08%, and the compressive elastic modulus of high-performance concrete decreases gradually with the increasing volume fraction of PVA fiber with appropriate content.

scholarly journals Compressive Strength Prediction of PVA Fiber-Reinforced Cementitious Composites Containing Nano-SiO2 Using BP Neural Network

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 521 ◽  
Author(s):  
Ting-Yu Liu ◽  
Peng Zhang ◽  
Juan Wang ◽  
Yi-Feng Ling
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Compressive Strength ◽  
Bp Neural Network ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Nano Sio2 ◽  
Pva Fiber ◽  
Fiber Reinforced Cementitious Composites

In this study, a method to optimize the mixing proportion of polyvinyl alcohol (PVA) fiber-reinforced cementitious composites and improve its compressive strength based on the Levenberg-Marquardt backpropagation (BP) neural network algorithm and genetic algorithm is proposed by adopting a three-layer neural network (TLNN) as a model and the genetic algorithm as an optimization tool. A TLNN was established to implement the complicated nonlinear relationship between the input (factors affecting the compressive strength of cementitious composite) and output (compressive strength). An orthogonal experiment was conducted to optimize the parameters of the BP neural network. Subsequently, the optimal BP neural network model was obtained. The genetic algorithm was used to obtain the optimum mix proportion of the cementitious composite. The optimization results were predicted by the trained neural network and verified. Mathematical calculations indicated that the BP neural network can precisely and practically demonstrate the nonlinear relationship between the cementitious composite and its mixture proportion and predict the compressive strength. The optimal mixing proportion of the PVA fiber-reinforced cementitious composites containing nano-SiO2 was obtained. The results indicate that the method used in this study can effectively predict and optimize the compressive strength of PVA fiber-reinforced cementitious composites containing nano-SiO2.

scholarly journals Effects of Modified Nano-SiO2 Particles on Properties of High-Performance Cement-Based Composites

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 646 ◽  
Author(s):  
Zhidan Rong ◽  
Mingyu Zhao ◽  
Yali Wang
Keyword(s):  
Mechanical Properties ◽  
Coupling Agent ◽  
High Performance ◽  
Silane Coupling Agent ◽  
Nano Sio2 ◽  
Nucleation Effect ◽  
Silane Coupling ◽  
Static Mechanical ◽  
Sio2 Particles ◽  
Static Mechanical Properties

In this research, silane coupling agent was used to modify the surface of nano-SiO2, particles and the effects of modified nano-SiO2 particles on the mechanical properties of high-performance cement-based composites and its mechanism were systematically studied. The results indicated that the optimum modification parameters were a coupling agent content of 10%, reaction temperature of 65 °C, and reaction time of 8 h. Compared with the unmodified nano-SiO2, the modified nano-SiO2 promoted and accelerated the hydration process of cement. The pozzolanic effect, filling effect, and nucleation effect of modified nano-SiO2 made the microstructure of the composite more compact, and thus improved static mechanical properties of cement-based composites.

scholarly journals Mix Design and Mechanical Properties of High-Performance Pervious Concrete

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2577 ◽  
Author(s):  
Chao-Wei Tang ◽  
Chiu-Kuei Cheng ◽  
Ching-Yuan Tsai
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Orthogonal Array ◽  
High Performance ◽  
Cementitious Material ◽  
Pervious Concrete ◽  
Mix Design ◽  
Fine Aggregate ◽  
Matrix Type ◽  
The Matrix

The mechanical properties of traditional pervious concrete are insufficient, which limits its application. In view of the imperfections of traditional permeable concrete in mechanics, this paper aimed to find a suitable material composition that can be used as a feasible mix design of high-performance pervious concrete, to essentially improve its mechanical properties. Based on the view that concrete is a two-phase material, in order to understand the rheological properties of the matrix, it was subjected to a rheological test, and then the filler aggregate was uniformly incorporated into the aforementioned matrix to further explore the composition and properties of the resulting pervious concrete. For the matrix, the orthogonal array employed was L16(45), which consisted of five factors, each with four levels. Base on the fluidity and compressive strength of the tested matrix, three groups of suitable matrixes mix proportions were selected to serve as the matrix type for pervious concrete mix proportion design. Then, an orthogonal array L9(34), which consisted of four controllable three-level factors, was adopted in the pervious concrete. The parameters investigated included the coarse aggregate size, fine aggregate content, matrix type, and aggregate-to-binder ratio. The test results demonstrate that the key factors affecting the compressive strength of the matrix and the pervious concrete were closely related to the cementitious material. In the matrix, the proportion of the cementitious material was the most important factor, while in the pervious concrete, the type of matrix was the most important factor.

Effect of PVA Fiber on Flexural Properties of High-Performance Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 262-265 ◽  
Author(s):  
Rui Min Liu ◽  
Wei Liu
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Axial Compressive Strength ◽  
Pva Fiber

In order to study the effect of the fraction of PVA fiber on the axial compressive strength and flexural properties of high performance concrete, a series of tests have been conducted in this study. The middle span deflection was measured by a micrometer with dial indicator, and six different concrete mixes have been chosen. Flexural properties include flexural strength and flexural modulus of elasticity. The mechanism of PVA fiber acting on axial compressive strength, flexural strength and flexural modulus of elasticity has been analyzed in details. The results indicate that there is a tendency of increase in the axial compressive strength and flexural strength when the fiber volume fraction is below 0.08%, and the flexural modulus of elasticity of high-performance concrete decrease gradually with the increase of fiber volume fraction.

Effect of freeze and thaw cycle on the mechanical properties of engineered cementitious composites with un-oiled fibers containing liquid and solid polymers

2022 ◽  
pp. 002199832110386
Author(s):  
Hadi Azadmanesh ◽  
Seyed Amir Hossein Hashemi ◽  
Seyed Hooman Ghasemi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bending Test ◽  
Styrene Butadiene Rubber ◽  
Uniaxial Tensile ◽  
Flexural Properties ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites ◽  
Freeze And Thaw ◽  
Thaw Cycle

Nowadays, the application of the engineered cementitious composites(ECC) is expected to highly develop. Due to the lack of access to oiled- polyvinyl alcohol (PVA) fibers in many parts of the world, the implementation of the ECC has contained many difficulties. In this study, to increase the mechanical properties of ECC with the use of un-oiled PVA fibers, the polymers of styrene butadiene rubber (SBR), and ethylene vinyl acetate (EVA) were taken into account to resolve the abovementioned issue. Herein, also in order to enhance the tensile and flexural properties of ECC, the cement was replaced by polymers. Accordingly, a total of 7 mix designs were planned to conduct the proposed tests. The compressive strength, uniaxial tensile strength, and three-point bending tests were performed on the ECC at their 28-day age with consideration of the freeze and thaw cycle. The results of this research illustrated that the use of polymers can enhance the tensile and flexural properties of the ECC with un-oiled PVA fibers. The tensile strain in this study increased by more than 3% after the application of the polymers. Furthermore, the compressive strength increased by more than 47 MPa, and the deflection at the mid-span reached more than 9 mm in the bending test. However, the results showed that the use of polymers was effective on the freeze and thaw cycle and almost preserved the mechanical properties of the ECC. SBR latex has higher compatibility with the ECC in comparison with EVA powder.

scholarly journals Fabrication of high-performance green hemp/polylactic acid fibre composites

2019 ◽  
Vol 14 ◽  
pp. 155892501983449 ◽  
Author(s):  
Zhenzhen Xu ◽  
Li Yang ◽  
Qignqing Ni ◽  
Fangtao Ruan ◽  
Hao Wang
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
High Performance ◽  
Weight Ratio ◽  
Specific Weight ◽  
Flexural Properties ◽  
Fibre Composites ◽  
Hemp Fibres ◽  
The Matrix ◽  
Forming Temperature

In this study, a novel compound lamination technique was applied to improve the mechanical properties of hemp fibre-reinforced polylactic acid composites. Polylactic acid fibres were blended with hemp fibres in a specific weight ratio in order to produce needled mats. Then, sections of the needled mat were stacked with several polylactic acid resin layers on either side, then formed hemp/polylactic acid composites through hot-pressing. The tensile and flexural properties of hemp/polylactic acid composites were tested according to ASTM standards. A multi-factor orthogonal analytical approach was adopted to discuss the effect of factors such as the hybrid ratio, forming temperature and pressure on mechanical properties of the developed green composites. The adhesion between the fibres and the matrix in the fracture surfaces and the thermal stability of the produced composites were observed via scanning electron microscopy and thermogravimetric analysis. The component analysis of composites was conducted by infrared spectra for confirming the contribution of polylactic acid. The results showed that adhesion between fibres and matrix was enhanced, as well as mechanical properties also improved, especially the tensile strength and flexural properties were obviously improved by utilizing this novel compounding technique.

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