Influence of Strength Attenuation for Silt Soil on the Fatigue Life of Semi-Rigid Base

Influence of water content on the resilience modulus for silt soil in Yellow River alluvial plane is studied by laboratory tests. And its found that resilience modulus decrease dramatically when the water content exceeds the optimum. So the subgrade cant support the pavement structure enough, which could make the fatigue life of semi-rigid base little than the design value. Basing on the distribution of the water content in real, the silt subgrade is divided into three parts in accordance with the difference of resilience modulus. Then, the tensile stress and fatigue life of semi-rigid base is gotten, and results show the strength decay of subgrade reduced the fatigue life of semi-rigid base up to 50%, which exposes the causes of early damage of semi-rigid base asphalt pavement on silt subgrade.

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Effect of steam autoclaving on laser sintered polyamide 12

Rapid Prototyping Journal ◽

10.1108/rpj-11-2019-0288 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

James Robert Wingham ◽

Maha Omran ◽

Joanna Shepherd ◽

Candice Majewski

Keyword(s):

Mechanical Properties ◽

Water Content ◽

Elongation At Break ◽

Content Type ◽

Polyamide 12 ◽

Root Cause ◽

Medical Sector ◽

Influence Of Water ◽

The Difference ◽

Direct Use

Purpose The use of laser sintering (LS) in the medical sector has increased dramatically in recent years. With the move towards direct use of these parts in clinical applications, there is a greater need to understand the effects of standard processes on the part properties. The purpose of this study is to determine the effect that steam sterilisation has on the mechanical properties of LS polyamide 12 parts. Design/methodology/approach The research presented here focusses on the effect of a single steam sterilisation cycle on the mechanical properties of polyamide 12 parts manufactured using LS. The influence of water content on the properties was investigated, with additional drying steps trialled to establish the potential to reverse any changes observed and to determine their root cause. Findings The results show that steam sterilisation has a significant effect on the mechanical properties of LS polyamide 12 parts, with a 39% reduction in elastic modulus, a 13% decrease in ultimate tensile strength and a 64% increase in the elongation at break. These properties were also all found to correlate with the water content, suggesting that this was the cause of the difference. The original properties of the parts were able to be recovered after oven drying. Practical implications These results show that with an additional drying step, LS polyamide 12 parts can be steam sterilised with no effect on the mechanical properties. Originality/value This is believed to be the first investigation into the effects of steam sterilisation in isolation on LS polyamide 12 parts, the first instance of drying parts to recover mechanical properties and the first instance of multiple water content measurements being directly linked to the mechanical properties.

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Test and Calculation Model of Thermal Conductivity of Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.905.314 ◽

2022 ◽

Vol 905 ◽

pp. 314-319

Author(s):

Lin Liu ◽

Jing Chang Wang

Keyword(s):

Thermal Conductivity ◽

Water Content ◽

Engineering Calculation ◽

Calculation Model ◽

Test Results ◽

Hydration Degree ◽

Plate Method ◽

Influence Of Water ◽

The Difference ◽

Calculated Model

In order to study the influence of water content and hydration degree on the thermal conductivity of concrete, based on the steady-state plate method, the influence of water content, temperature, hydration degree and other factors on the thermal conductivity of early concrete was studied, and the calculation model of thermal conductivity of early concrete was established according to the test results and influence rules. The results show that there is a linear relationship between the thermal conductivity and water content at 28d, the higher the hydration degree is, the lower the thermal conductivity of concrete is; the difference between the measured value and the calculated model value is small, and the calculation formula can meet the requirements of engineering calculation.

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Numerical analysis of factors affecting the fatigue life of asphalt pavement with semi-rigid base

Functional Pavement Design ◽

10.1201/9781315643274-96 ◽

2016 ◽

pp. 879-888

Author(s):

T.Y. Zhu ◽

S.Q. Wang ◽

X.M. Huang

Keyword(s):

Fatigue Life ◽

Numerical Analysis ◽

Asphalt Pavement ◽

Rigid Base ◽

Factors Affecting

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Mechanics Analysis of Semi-Rigid Subgrade Pavement Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.580-583.105 ◽

2014 ◽

Vol 580-583 ◽

pp. 105-108

Author(s):

Li Ya Su

Keyword(s):

Tensile Stress ◽

Elasticity Modulus ◽

Asphalt Pavement ◽

Vertical Displacement ◽

Pavement Design ◽

Rigid Base ◽

Mechanics Analysis ◽

Pavement Structure ◽

Early Damage

The semi-rigid base asphalt pavement structure was choose often used to the highway in our country, but the semi-rigid base asphalt pavement early damage almost has become a common phenomenon.In this paper, the rule and trend of mechanics response about pavement structure (the vertical displacement and tensile stress) were analyzed under the semi-rigid base choose different elasticity modulus and thickness by ANSYS for muti-layer foundation of semi-rigid base pavement design to provide reference.

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Influence of Water Content on the Strength of Silt Soil in Yellow River Alluvial Plain

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.256-259.481 ◽

2012 ◽

Vol 256-259 ◽

pp. 481-487

Author(s):

Xiao Ming Yi ◽

Song Gen Wang ◽

Zhen Qing Liu ◽

Gang Xu

Keyword(s):

Elastic Modulus ◽

Water Content ◽

Yellow River ◽

Friction Angle ◽

Cohesive Soil ◽

High Water ◽

Alluvial Plain ◽

High Water Content ◽

Optimum Water Content ◽

Influence Of Water

Hydrophilic characteristic of silt soil in Yellow River alluvial plain was studied in order to reveal the water content changes of silt. Then strength tests were used to research how engineering parameters such as elastic modulus, cohesion and friction angle change at different water content. The results show that high permeability coefficient and strong capillary are main factors to increase the water content, and the influence of capillary rising is greater than that of rainfall infiltration. The strength characteristic of silt soil is similar to the character of non-cohesive soil in low water content and that of clay in high water content. If the water content is greater than optimum water content, the elastic modulus and cohesion of silt shall decay obviously. Friction angle decreases dramatically as well, when the soil is saturated.

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