Effect of Core Box Temperature, Hot-Air Parameters and Micro-Silica Powder on Tensile Strength of Sand Core

2021 ◽  
Author(s):  
Fang-hai Xin ◽  
Wei-hua Liu ◽  
Lai Song ◽  
Ying-min Li
Keyword(s):  
Tensile Strength ◽  
Silica Powder ◽  
Hot Air ◽  
Sand Core ◽  
Micro Silica

scholarly journals Influence of Partial Replacement of Micro-Silica by Fly-Ash on Strength Properties of Reactive Powder Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 2932-2937
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Cementitious Materials ◽  
Partial Replacement ◽  
Reactive Powder Concrete ◽  
Experimental Investigations ◽  
Reactive Powder ◽  
Micro Silica

Reactive powder concrete (RPC) is the ultra-high strength concrete made by cementitious materials like silica fumes, cement etc. The coarse aggregates are completely replaced by quartz sand. Steel fibers which are optional are added to enhance the ductility. Market survey has shown that micro-silica is not so easily available and relatively costly. Therefore an attempt is made to experimentally investigate the reduction of micro-silica content by replacing it with fly-ash and mechanical properties of modified RPC are investigated. Experimental investigations show that compressive strength decreases gradually with addition of the fly ash. With 10 per cent replacement of micro silica, the flexural and tensile strength showed 40 and 46 per cent increase in the respective strength, though the decrease in the compressive strength was observed to be about 20 per cent. For further percentage of replacement, there was substantial drop in compressive, flexural as well as tensile strength. The experimental results thereby indicates that utilisation of fly-ash as a partial replacement to micro silica up to 10 per cent in RPC is feasible and shows quite acceptable mechanical performance with the advantage of utilisation of fly-ash in replacement of micro-silica.

Preparation and Properties of Acidified Prevulcanized Natural Rubber Latex

2014 ◽  
Vol 997 ◽  
pp. 239-242
Author(s):  
Guang Lu ◽  
He Ping Yu ◽  
Yong Zhou Wang ◽  
Yong Yue Luo ◽  
Zong Qiang Zeng
Keyword(s):  
Tensile Strength ◽  
Acetic Acid ◽  
Natural Rubber ◽  
Acid Content ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Acetic Acid Content ◽  
Hot Air ◽  
Aging Resistance

After a maturation of three days at ambient temperature, the sulfur-prevulcanized natural rubber latex (SNRL) was stabilized by 20wt% Peregal O, and then acidified with the 36wt% acetic acid by a ratio of 5, 15, 25, 35 and 45 g of 36wt% acetic acid to 100g SNRL, to obtain acidified prevulcanized NR latex (ASNRL) with different acidity, respectively. The viscosity of ASNRL increased, while the nitrogen content decreased, with the increment of acetic acid content and the decrease in pH; for unaged samples, the tensile strength, elongation at break, 300% and 500% moduli of the ASNRL films were only slightly lower than those of SNRL film; however the hot-air aging resistance decreased with the increment of acetic acid content.

Study on Thermal Oxidative Aging of Nitrile Rubber

2013 ◽  
Vol 299 ◽  
pp. 199-202 ◽  
Author(s):  
Xiao Gang Li ◽  
Yu Long Zhang ◽  
Ming Yuan Yang
Keyword(s):  
Tensile Strength ◽  
Accelerated Aging ◽  
Tensile Fracture ◽  
Oxidative Aging ◽  
Polymer Fracture ◽  
Hot Air ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Fracture Appearance ◽  
Thermal Oxidative Aging

This paper studies the changing regularity of hardness and tensile strength, through accelerated aging test of NBR in hot air. The tensile fracture appearance of test samples aging for different time is observed. The results indicate that NBR’s hardness increases firstly and then decreases and finally increases again, tensile strength presents escalating trend and the change of tensile fracture corresponds with polymer fracture mechanism of elastic material.

Investigation of the properties of polynorbornene rubber/EPDM blends

2016 ◽  
Vol 49 (7) ◽  
pp. 560-573 ◽  
Author(s):  
Ming Qu ◽  
Yan Ma ◽  
Chengliang Li ◽  
Xinyan Shi
Keyword(s):  
Tensile Strength ◽  
Mechanical Analysis ◽  
Cross Linking ◽  
Yield Behavior ◽  
Hot Air ◽  
Paraffin Oil ◽  
Aging Resistance ◽  
Higher Temperature ◽  
Ethylene Propylene Diene Rubber ◽  
Diene Rubber

Polynorbornene rubbers (PNRs) used in this article were commercial compounds of polynorbornene filled with paraffin oil and fillers. The properties of PNR and ethylene-propylene-diene rubber (EPDM2650) blends with ratios of 100/0, 75/25, 50/50, 25/75, and 0/100 were investigated. Blends were cured by sulfur and accelerator at 150°C and 160°C, respectively. Moving die rheometer, differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA), and rubber process analyzer were used to examine the properties of the blends. The PNR exhibited significant reversion that was reduced by blending with EPDM. The thermal cross-linking of PNR occurred during hot air aging. The hot air aging resistance of PNR was improved by blending with EPDM. After 72 h of ozone aging, no obvious cracks were observed on the surface. The DMA results showed that the effective damping temperature range (tanδ ≥ 0.3) of vulcanized PNR was the broadest at 113°Cand then narrowed at higher temperature as the content of EPDM in the blend increased. With an increase in the ratio of EPDM, the glass transition temperature ( Tg) of EPDM moved to higher temperatures, as measured by DSC. The tensile strength of neat PNR is the greatest. PNR/EPDM = 75/25 blends showed yield behavior as the Tg of PNR moved to the higher temperature. These effects are attributed to a transfer of the extended oil from the PNR to the EPDM.

Effect of Aging on Mechanical Properties of Natural Rubber Latex Products Filled with Alkanolamide-Modified Cassava Peel Waste Powder (CPWP)

2015 ◽  
Vol 1123 ◽  
pp. 387-390 ◽  
Author(s):  
Hamidah Harahap ◽  
Adrian Hartanto ◽  
Kelvin Hadinatan ◽  
Indra Surya ◽  
Baharin Azahari
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Hot Air ◽  
Before And After ◽  
Cassava Peel

The effect of aging on mechanical properties of natural rubber latex (NRL) products filled with alkanolamide-modified cassava peel waste powder (CPWP) was studied. CPWP used as fillers was prepared by milling and sieving it until the size of 100 mesh. The powder then was dispersed in a suspension containing water and alkanolamide in order to modify the prepared powders. The dispersion system of 10 pphr (part per hundred rubber) then was added into NRL matrix followed by pre-vulcanization at 70°C for 10 minutes. The NRL compound then were casted into films by coagulant dipping method then dried at 120°C for 10 minutes. Afterwards, the films were allowed to cool at room temperature for 24 hours before being aged in a circulation of hot air for 24 hours at 70°C. The properties such as tensile strength, tensile modulus, and elongation at break were evaluated between the aged samples and the unaged samples. From this study, it showed that the aged films have increasing value of tensile strength and tensile modulus while the value of elongation at break decreases. These datas are supported by Scanning Electron Microscope (SEM) micrographs which indicate that the change of morphology in NRL films occurs before and after aging.

scholarly journals Performance of Modified Rubber Aggregate Concrete with GGBS and Silica

2019 ◽  
Vol 9 (2) ◽  
pp. 2438-2441
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Research Programme ◽  
Conventional Concrete ◽  
Aggregate Concrete ◽  
Waste Rubber ◽  
Strength And Durability ◽  
Micro Silica

Transfer of tyre rubber suit a tremendous difficulty in India step by step. Analysts are attempting to utilize waste rubber in structural building venture from numerous days back. When coarse aggregate was replaced with 20% chipped rubber it was found that the optimum replacement is5% but still there is a deficit in some strength from conventional concrete. This research programme tries to minimise this gap by adding extra 5% micro silica of the weight of cement and also by replacing 40% of cement by GGBS. Here cubes, cylinders, and prisms were casted to test compressive strength, tensile strength, flexural strength, and durability against heat and were observed after 28 days and 56 days

scholarly journals LABORATORY TESTS ON THE STRENGTHENING OF WET-MIX SHOTCRETE LINING WITH THE USE OF NANOMATERIALS

2021 ◽  
Vol 36 (1) ◽  
pp. 49-59
Author(s):  
Hamid Kalhori ◽  
Raheb Bagherpour ◽  
Mohammad Amir Akhlaghi ◽  
Sayed Mohsen Mirdamadi ◽  
Mehdi Nasiri Sarvi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Laboratory Tests ◽  
Size Range ◽  
Maximum Increase ◽  
Nano Clay ◽  
Cement Based Materials ◽  
Cast Concrete ◽  
Shotcrete Lining ◽  
Micro Silica

Adding nanomaterials to concrete extends the size range of constituent particles well into nano-scale dimensions, which could help the compacting of particles in cement-based materials. Regarding the differences between shotcrete and cast concrete, in this study, the properties of shotcrete with nano and micro-silica and nano-clay were experimentally studied. The micro and nanomaterials have been added at different percentages (6%, 9%, and 12%) to a shotcrete paste. The comparison was based on the uniaxial compressive strength, flexural strength, tensile strength, and porosity tests of different specimens. The results indicated that the maximum increase in compressive, flexural, and tensile strengths of shotcrete was related to 12% nano-SiO2, while for 12% nano-clay, all of these strengths were decreased at 28 days. The optimum percentage for shotcrete substitution by nano-clay was established to be 6%. Also, the application of the nanomaterials led to a decrease in the water absorption and porosity of shotcrete. Eventually, the results revealed that the improvement of mechanical properties by the introduction of the nanomaterials in shotcrete could be satisfactory.

An Experimental Analysis to Determine the Effects of Welding Parameters on Tensile Strength of Hot Air Welded Poly Vinyl Chloride (PVC) Plastic

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Md Shakibul Haque ◽  
Inayat Hussain ◽  
Athar Hussain ◽  
Mohd Anees Siddiqui
Keyword(s):  
Tensile Strength ◽  
Vinyl Chloride ◽  
Experimental Modeling ◽  
Welding Parameters ◽  
Model Parameters ◽  
Air Flow Rate ◽  
Hot Air ◽  
Poly Vinyl Chloride ◽  
Best Fit ◽  
Significant Factors

The present work has been carried out to study the effect of some input parameters on the desired response in the Poly Vinyl Chloride (PVC) plastic, welded by hot air technique. The effect of hot air temperature, welding speed and air flow rate has been evaluated on the Tensile Strength, of the weld bead deposited. These responses have been analysed using the analysis of variance (ANOVA) and experimental modeling. Plots of significant factors and experimental modeling have been used to determine the best fit relationship between the responses and the model parameters using MINITAB 17. This has been used to determine the most influencing parameter.

scholarly journals Relationship between splitting tensile and compressive strengths for self-compacting concrete containing nano- and micro silica

2018 ◽  
Vol 162 ◽  
pp. 02013 ◽  
Author(s):  
Ali Jaber ◽  
Iqbal Gorgis ◽  
Maan Hassan
Keyword(s):  
Tensile Strength ◽  
Absolute Error ◽  
International Literature ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Direct Tension ◽  
Self Consolidating Concrete ◽  
Using Data ◽  
Micro Silica ◽  
The Relationship

This paper describes the relationship between splitting tensile strength and compressive strength of self-consolidating concrete using data collected from laboratory specimens tested at standard conditions. The results were then compared with some expressions published in international literature. The investigated variables included: type of cement, percentage of nanosilica and percentage of microsilica as a cement replacement by weight. In spite of concrete not being designed to resist direct tension the knowledge of tensile strength is needed to estimate the cracking load. In the absence of test results an estimate of the tensile strength may be obtained by using the relationship proposed. The verification of the proposed formula based on experimental data was estimated by means of the integral absolute error (IAE). The output of this study has provided a better understanding of the correlation between splitting and compressive strengths of SCCs and the effect of some related variables on the resultant behavior, which has therefore, helped to generate new expression with better accuracy.

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