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.

Effect of Fly Ash on the early Age Cracking Performance of Cement Paste

2014 ◽  
Vol 584-586 ◽  
pp. 894-898
Author(s):  
Ping Zhang ◽  
Guan Guo Liu ◽  
Chao Ming Pang ◽  
Bing Du ◽  
Hong Gen Qin
Keyword(s):  
Computed Tomography ◽  
Fly Ash ◽  
Cement Paste ◽  
Test Method ◽  
Early Age ◽  
Cement Ratio ◽  
X Ray ◽  
Cracking Performance ◽  
X Ray Computed ◽  
Ct Test

The X ray computed tomography (X-CT) was applied to test the cracking resistance of cement paste, and the hydration process was monitored to study the effect of fly ash on the early age cracking performance. The results showed that the hydration heat reduced with the increase of fly ash under the same water-cement ratio. Within 24h, the porosity increased with time. The addition of fly ash increased the proportion of large holes and then changed the internal stress state. Using X-CT test method and by comparing the number of cracks, the sample with 20% FA was found to have the most serious cracks, whereas the sample with 30% FA had the best crack resistance.

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.

scholarly journals Study on estimation of creep behaviour of concrete at early age considering temperature effect

2019 ◽  
Vol 289 ◽  
pp. 10010
Author(s):  
Kayo Ohashi ◽  
Jun-ichi Arai ◽  
Toshiaki Mizobuchi
Keyword(s):  
Thermal Stress ◽  
Temperature Effect ◽  
Creep Strain ◽  
Prediction Accuracy ◽  
Creep Behaviour ◽  
Test Method ◽  
Control Measures ◽  
Experimental Result ◽  
Early Age ◽  
And Control

Clarifying the creep behaviour of concrete at early age not only improves the accuracy of temperature stress analysis but also contributes to prediction accuracy and control measures in cracks caused by thermal stress. However, most past researches on creep behaviour were investigated after 28 days. Currently, it is difficult to accurately perceive the creep behaviour of concrete at an early age in the test method of creep which is generally carried out. Therefore, it is necessary to evaluate the creep behaviour of concrete at early age and to establish a convenient test method to estimate the creep behaviour. Therefore, in this study, experiments were carried out for concrete at early age within one week. As the result of the experiments, it was shown that the creep strain is proportional to the load stress of concrete at an early age and the strain of specific creep decreases as the loaded age increases. In addition, based on the experimental results, an estimation equation for creep strain at early age was proposed. Within the scope of this experimental result, it was confirmed that the estimation equation proposed in this study accurately represented the creep behaviour of concrete at early age.

scholarly journals A linear test method for determining early-age shrinkage of concrete

2008 ◽  
Vol 60 (10) ◽  
pp. 747-757 ◽  
Author(s):  
M. D. Newlands ◽  
K. A. Paine ◽  
N. A. Vemuri ◽  
R. K. Dhir
Keyword(s):  
Test Method ◽  
Early Age

scholarly journals Experimental Study to Determine the Failure Criteria of Concrete at Its Early-Age

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Hongyan Ding ◽  
Lei Zhang ◽  
Puyang Zhang
Keyword(s):  
Compressive Strength ◽  
Constitutive Relation ◽  
Concrete Structures ◽  
Failure Criteria ◽  
Early Age ◽  
Construction Technique ◽  
Concrete Material ◽  
Axial Tensile ◽  
Mathematical Relation ◽  
Early Age Concrete

The failure criteria and the constitutive relation of materials for an early-age concrete are the most common reasons to conduct the nonlinear analysis and to assess the concrete structures during the construction stage. The delay of theoretical advancement in this field resulted into a mismatch between the rough theories and the advanced algorithms, which were adopted for the estimation and analysis of early-age concrete structures. It is often impossible to find an appropriate way to determine the failure criteria and its constitutive relation that may serve as a baseline. As a consequence, the development and the application of advanced techniques of construction, for example, early dismantling construction technique of formwork, have severely been restrained. Therefore, the study of the failure criteria and its constitutive relation of concrete materials at early-age are important. In this paper, the cubic compressive strength, the prismatic compressive strength, and the axial tensile strength are determined by carrying out a strength test on C20 concrete material at an early-age. Next, the failure criteria of C20 early-age concrete material in the octahedral stress space have been studied and analyzed by using the regression analysis and by deriving the mathematical relation.

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.

Early Age Cracking Characteristic of Concrete with Compound Admixtures

2013 ◽  
Vol 325-326 ◽  
pp. 71-74
Author(s):  
Yun Feng Li ◽  
Dong Sheng Zhang ◽  
Li Xu
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Steel Slag ◽  
Test Method ◽  
Mineral Admixture ◽  
Early Age ◽  
Furnace Slag

The shrinkage cracking of concrete plays an important role to the accelerated deterioration and shortening the service life of concrete structures. The mineral admixture will be a perfect component of high performance concrete and its utilization will be a valuable resource for recycling. Early age cracking characteristics of concrete with compound admixtures, such as steel slag, blast furnace slag, fly ash, are studied in this paper using plate test method. The better anti-cracking performance of concrete will be realized when blast furnace slag replacing cement at 30%, steel slag and fly ash as the equal mixture components replacing cement at 30%, three kinds of admixtures replacing cement at 30% under the proper proportion.

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