The Research of GGBS’ Influence on the Cracking Resistance of Concrete

2014 ◽  
Vol 919-921 ◽  
pp. 1864-1867
Author(s):  
Yan Liu ◽  
Dao Xun Ma
Keyword(s):  
Test Method ◽  
Early Age ◽  
Cracking Resistance ◽  
Volume Stability ◽  
The Impact

The aim of this paper is to study the impact of GGBS on the early age cracking resistance of concrete. To assess the volume stability of premixed concrete under different dosage of GGBS an innovative cracking test method is adopted, and the causes and effect mechanisms of that are analyzed.

Effect of Water-to-Cement Ratio on Cracking Resistance of Concrete at Early Age in Restrained Ring Specimens

2021 ◽  
Author(s):  
Dejian Shen ◽  
Yang Jiao ◽  
Ci Liu ◽  
Jiacheng Kang ◽  
Xiaojian Tang
Keyword(s):  
Development Rate ◽  
Ring Test ◽  
Engineering Practice ◽  
Early Age ◽  
Cracking Resistance ◽  
Multiple Parameters ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Study Results ◽  
The Impact

Nowadays, low water-to-cement (w/c) ratio has been put into widespread use in engineering practice. However, low w/c ratio may give rise to high self-desiccation, which may lead to the decrease of early-age cracking resistance. Investigating the impact of w/c ratio on cracking resistance is utterly meaningful to understand the cracking mechanism of concrete better. However, the corresponding investigations remain lacking, especially when the ring test is utilized. Ring tests for three concrete mixtures with different w/c ratios were conducted to investigate the early-age cracking resistance of concrete from multiple parameters in the present study. Results showed that: (1) the development rate of shrinkage of concrete for Mixture W50 was slower than Mixture W33 and W40; (2) the value and development rate of residual stress of concrete decreased when the w/c ratio increased; (3) the relaxed stress for all mixtures developed rapidly at very early age, and reached the maximum quickly; (4) the cracking resistance of concrete increased as the w/c ratio increased at early age.

The Research on the Crack Performance of Airport Pavement Concrete with the Mineral Admixture of Fly Ash

2013 ◽  
Vol 807-809 ◽  
pp. 2699-2702 ◽  
Author(s):  
Yan Liu ◽  
Bin Xiao
Keyword(s):  
Fly Ash ◽  
Test Method ◽  
Mineral Admixture ◽  
Early Age ◽  
Concrete Material ◽  
Volume Stability ◽  
Airport Pavement ◽  
Pavement Concrete

This paper studies the influence of fly ash with different dosage and grades on the crack performance of airport pavement concrete. In order to test airport pavement concrete material accurately and quickly, Dumbbell Test Method was introduced in its early-age from pouring. Dumbbell Test Method is able to evaluate the effect of fly ash with different grades and dosage on volume stability of airport pavement concrete. This paper also studied the mechanism of the influence of fly ash crack performance of airport pavement concrete.

The Influence of Fly Ash on the Crack Performance of Airport Pavement Concrete by Dumbbell Test Method

2013 ◽  
Vol 724-725 ◽  
pp. 1719-1722
Author(s):  
Yan Liu
Keyword(s):  
Fly Ash ◽  
Test Method ◽  
Early Age ◽  
Concrete Material ◽  
Volume Stability ◽  
Airport Pavement ◽  
Pavement Concrete

In this paper, the influence of fly ash with different dosage and grades on the crack performance of airport pavement concrete was studied. Its exercise new Dumbbell Test Method could make the airport pavement concrete material be tested accurately and quickly during early-age from pouring. The effect of fly ash with different grades and dosage on volume stability of airport pavement concrete was evaluated by Dumbbell Test Method. Also the paper analyzes the mechanism of the influence of fly ash on the crack performance of airport pavement concrete.

The Influence of GGBS on the Shrinkage Performance of Concrete

2014 ◽  
Vol 919-921 ◽  
pp. 1860-1863
Author(s):  
Yan Liu ◽  
Dao Xun Ma
Keyword(s):  
Early Age ◽  
Volume Stability ◽  
Testing Method ◽  
The Impact

This paper studies the impact of different dosage of GGBS on the early age and later shrinkage deformation of concrete. Through the testing method of early age shrinkage of concrete the volume stability of shrinkage of concrete under different dosage of GGBS is evaluated, and the causes and effect mechanisms of that are analyzed.

scholarly journals Evaluation of Energy Absorption Capabilities of Polyethylene Foam under Impact Deformation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3613
Author(s):  
Baohui Yang ◽  
Yangjie Zuo ◽  
Zhengping Chang
Keyword(s):  
Energy Absorption ◽  
Failure Modes ◽  
High Strain ◽  
Early Stage ◽  
High Energy ◽  
Test Method ◽  
Test Theory ◽  
Strain Rates ◽  
Impact Properties ◽  
The Impact

Foams are widely used in protective applications requiring high energy absorption under impact, and evaluating impact properties of foams is vital. Therefore, a novel test method based on a shock tube was developed to investigate the impact properties of closed-cell polyethylene (PE) foams at strain rates over 6000 s−1, and the test theory is presented. Based on the test method, the failure progress and final failure modes of PE foams are discussed. Moreover, energy absorption capabilities of PE foams were assessed under both quasi-static and high strain rate loading conditions. The results showed that the foam exhibited a nonuniform deformation along the specimen length under high strain rates. The energy absorption rate of PE foam increased with the increasing of strain rates. The specimen energy absorption varied linearly in the early stage and then increased rapidly, corresponding to a uniform compression process. However, in the shock wave deformation process, the energy absorption capacity of the foam maintained a good stability and exhibited the best energy absorption state when the speed was higher than 26 m/s. This stable energy absorption state disappeared until the speed was lower than 1.3 m/s. The loading speed exhibited an obvious influence on energy density.

scholarly journals Laboratory experiment on the nano-TiO2 photocatalytic degradation effect of road surface oil pollution

2020 ◽  
Vol 9 (1) ◽  
pp. 922-933
Author(s):  
Qing’e Wang ◽  
Kai Zheng ◽  
Huanan Yu ◽  
Luwei Zhao ◽  
Xuan Zhu ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Oil Pollution ◽  
Road Surface ◽  
Test Method ◽  
Driving Safety ◽  
The Road ◽  
Road Surfaces ◽  
The Many ◽  
The Impact ◽  
Degradation Effect

AbstractOil leak from vehicles is one of the most common pollution types of the road. The spilled oil could be retained on the surface and spread in the air voids of the road, which results in a decrease in the friction coefficient of the road, affects driving safety, and causes damage to pavement materials over time. Photocatalytic degradation through nano-TiO2 is a safe, long-lasting, and sustainable technology among the many methods for treating oil contamination on road surfaces. In this study, the nano-TiO2 photocatalytic degradation effect of road surface oil pollution was evaluated through the lab experiment. First, a glass dish was used as a substrate to determine the basic working condition of the test; then, a test method considering the impact of different oil erosion degrees was proposed to eliminate the effect of oil erosion on asphalt pavement and leakage on cement pavement, which led to the development of a lab test method for the nano-TiO2 photocatalytic degradation effect of oil pollution on different road surfaces.

The Experiment on Soil Water Characteristic Curve Considering the Effect of Urea Concentration

2014 ◽  
Vol 919-921 ◽  
pp. 795-799
Author(s):  
Gai Qing Dai ◽  
Dong Fang Tian ◽  
Yao Ruan ◽  
Lang Tian ◽  
You Le Wang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Urea Concentration ◽  
Test Method ◽  
Materials Selection ◽  
Valuable Data ◽  
Soil Water Characteristic Curve ◽  
Concentration Test ◽  
The Impact

A new soil water characteristic curve (SWCC) experiment contemplating urea concentration is presented in the paper. We focus on the impact of the SWCC considering urea concentration test method for materials selection and introduction, experimental results, and finally, we have conducted some experiments of SWCC and obtained some valuable data which could affect urea concentration. By using linear fitting, an exponential function between water content and suction and urea concentration is established.

Experimental Determination of Dynamic Characteristics of a Full Size Gas Turbine Tilting-Pad Journal Bearing by an Impact Test Method

1991 ◽  
Author(s):  
S. H. Chan ◽  
M. F. White
Keyword(s):  
Gas Turbine ◽  
Impact Test ◽  
Journal Bearing ◽  
Estimation Procedure ◽  
Response Spectra ◽  
Test Method ◽  
Full Size ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearing ◽  
The Impact

Abstract Measurements have been taken on an experimental rotor-bearing test rig which consists of a full size gas turbine shaft supported by two five-pad tilting-pad journal bearings. The impact test method was applied by exciting one end of the shaft in-situ by means of a hammer blow. Impact forces and response displacements were collected and analysed with suitable corrections for runout effect. Averaged frequency response spectra thus obtained were used in a parameter estimation procedure to calculate the dynamic coefficients of the tested tilting-pad journal bearing. An analytical single degree-of-freedom model was employed and one of the input parameters in the mechanical model, the effective mass, was found to significantly influence the estimated results. The measured stiffness and damping coefficients are compared with results predicted by a bearing design program. Possible sources of discrepancies between experimental and theoretical results are discussed.

Dumbbell Test Method for Evaluation of the Early Age Cracking Property of Concrete Material by Stress Risers

2012 ◽  
Vol 503-504 ◽  
pp. 473-476
Author(s):  
Yan Liu ◽  
Zhi Gang Luo ◽  
Jie Cao
Keyword(s):  
Test Method ◽  
Early Age ◽  
Construction Site ◽  
Quick Method ◽  
Concrete Material ◽  
Stress Risers ◽  
Test Technology ◽  
Cracking Performance ◽  
Simulated Test ◽  
Job Site

This article develops one new test technology, dumbbell test method, for evaluation of the early age cracking property of Concrete Material under constraint conditions. Its exercise of stress risers could lead concrete to crack quickly, providing a quick method to evaluate the early age crack performance of concrete material and to perform simulated test at job site conveniently. By this method, the anti-cracking performance of different concrete material can be evaluated quickly in the construction site.

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