Research on Performance of Cement Stabilized Skeleton-Dense Structure Aggregate Base Course Material

2011 ◽  
Vol 194-196 ◽  
pp. 1089-1094
Author(s):  
Li Qun Hu ◽  
Ai Min Sha
Keyword(s):  
Cement Content ◽  
Thermal Shrinkage ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Dense Structure ◽  
Base Course Material ◽  
Course Material ◽  
Base Course ◽  
Aggregate Base ◽  
Shrinkage Coefficient

Laboratory tests were conducted to evaluate the performance of cement stabilized “skeleton-dense structure” aggregate and conventional “suspended-dense structure” aggregate. In this study, both of the aggregates above were stabilized by cement with different cement content (2%, 3%, 4%, 5% and 6%). Performances of the prepared specimens were studied in terms of compaction property, 7 day unconfined compressive strength (UCS), thermal shrinkage coefficient and 30 min erosion quantity. Results indicated that the maximum dry density of cement stabilized “skeleton-dense structure” aggregate is bigger than that of cement stabilized “suspended-dense structure” aggregate slightly. On the contrary, the optimum moisture content of the former is slightly smaller than that of the latter one. Along with the increase of cement content, the 7 day UCS and thermal shrinkage coefficient of cement stabilized two aggregates were all increase, and 30 min erosion quantity of cement stabilized two aggregates were all decrease. At the same cement content level, the 7 day UCS of cement stabilized “skeleton-dense structure” aggregate is greater than that of cement stabilized “suspended-dense structure” aggregate, and the thermal shrinkage coefficient and erosion quantity in 30 min of the former is smaller than that of the latter.

Evaluating the Impact of Coarse Aggregate Content on Properties of Cement Treated Base

2011 ◽  
Vol 52-54 ◽  
pp. 729-733 ◽  
Author(s):  
Li Qun Hu ◽  
Ai Min Sha
Keyword(s):  
Coarse Aggregate ◽  
Thermal Shrinkage ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Coarse Aggregates ◽  
Aggregate Content ◽  
Base Course ◽  
Aggregate Base ◽  
The Impact ◽  
Shrinkage Coefficient

This paper mainly presents the study on the properties of cement treated aggregate with different coarse aggregate content. The test specimens which contain 75%, 70%, 65%, 60% and 55% of coarse aggregates were made and the 7d, 28d, and 90d unconfined compressive strengths (UCS), 28d thremal shrinkage coefficient, as well as 90d anti-erosion performance were tested. Results show that with the increase of coarse aggregate, the maximum dry density (MDD)of the cement treated aggregate mixture increased slowly at first to reached the peak value and then decreased rapidly; The optimum moisture content (OMC) declined with the increase of coarse aggregate content; In order to enhance the UCS of cement treated aggregate, coarse aggregate of mixture can be increased to some extent, but too much coarse aggregate will increase the void of the specimen and lead to lower UCS; Increasing the content of coarse aggregate is able to decrease the thermal shrinkage coefficient and erosion quantity of 30 min of the specimens. This is favourable to enhance the cracking resistance and anti-erosion performance of cement treated aggregate base course.

scholarly journals Influence of Laboratory Compaction Method on Compaction and Strength Characteristics of Unbound and Cement-Bound Mixtures

2021 ◽  
Vol 11 (11) ◽  
pp. 4750
Author(s):  
Matija Zvonarić ◽  
Ivana Barišić ◽  
Mario Galić ◽  
Krunoslav Minažek
Keyword(s):  
Cement Content ◽  
Road Construction ◽  
Test Methods ◽  
Strength Characteristics ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Optimal Moisture Content ◽  
Proctor Test ◽  
Base Course ◽  
Compaction Method

During road construction, granular materials for the unbound base course (UBC) and cement-bound base course (CBC) are mostly compacted by vibratory rollers. A widespread laboratory test for determining the optimal moisture content (OMC) and maximum dry density (MDD) of the mixture for installation in UBC and CBC is the Proctor test. Considering that the Proctor test does not produce any vibrations during compaction, this paper compares the Proctor test and the vibrating hammer test. The examination was conducted on UBC and CBC with varying cement content and aggregate types. All mixtures were compacted by both methods with the aim of determining the compaction and strength characteristics. The results indicated the high comparability of the two test methods for mixtures with natural aggregate in terms of MDD, OMC, density and strength characteristics (California bearing ratio (CBR) for UBC and 28-day compressive strength for CBC). For mixtures with higher cement content, the OMC difference depending on the laboratory compaction method used can be significant, so the laboratory compaction method should be chosen carefully, particularly for moisture-susceptible materials. This paper also reveals that by increasing the proportion of rubber in the mixture, the compaction and strength characteristics differ significantly due to the compaction method. Therefore, when using alternative and insufficiently researched materials, the compaction method should also be chosen carefully.

scholarly journals Deep Neural Network Models for the Prediction of the Aggregate Base Course Compaction Parameters

Designs ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 78
Author(s):  
Kareem Othman
Keyword(s):  
Neural Network ◽  
Network Models ◽  
Activation Function ◽  
Dry Density ◽  
Activation Functions ◽  
Neural Network Models ◽  
Maximum Dry Density ◽  
Base Course ◽  
Aggregate Base ◽  
The Impact

Laboratory tests for the estimation of the compaction parameters, namely the maximum dry density (MDD) and optimum moisture content (OMC) are time-consuming and costly. Thus, this paper employs the artificial neural network technique for the prediction of the OMC and MDD for the aggregate base course from relatively easier index properties tests. The grain size distribution, plastic limit, and liquid limits are used as the inputs for the development of the ANNs. In this study, multiple ANNs (240 ANNs) are tested to choose the optimum ANN that produces the best predictions. This paper focuses on studying the impact of three different activation functions: number of hidden layers, number of neurons per hidden layer on the predictions, and heatmaps are generated to compare the performance of every ANN with different settings. Results show that the optimum ANN hyperparameters change depending on the predicted parameter. Additionally, the hyperbolic tangent activation is the most efficient activation function as it outperforms the other two activation functions. Additionally, the simplest ANN architectures results in the best predictions, as the performance of the ANNs deteriorates with the increase in the number of hidden layers or the number of neurons per hidden layers.

scholarly journals EFFECTS OF FREEZE-THAWING ON BEARING CAPACITY OF GRANULAR BASE COURSE MATERIAL

2012 ◽  
Vol 68 (3) ◽  
pp. I_115-I_122
Author(s):  
Shinichiro KAWABATA ◽  
Tatsuya ISHIKAWA ◽  
Takumi MURAYAMA ◽  
Shuichi KAMEYAMA
Keyword(s):  
Bearing Capacity ◽  
Base Course Material ◽  
Course Material ◽  
Base Course ◽  
Granular Base

The Research on the Application of the Steel Slag Produced by the Converters of Jigang Group Co. Ltd on Base Course

2012 ◽  
Vol 178-181 ◽  
pp. 1699-1705
Author(s):  
Fa Liang Lu ◽  
Jin Li
Keyword(s):  
Mechanical Property ◽  
Unconfined Compressive Strength ◽  
Steel Slag ◽  
Coal Ash ◽  
Strength Test ◽  
Water Stability ◽  
Compressive Strength Test ◽  
Base Course Material ◽  
Course Material ◽  
Base Course

To test and inspect the chemical compositions and mechanical properties of the steel slag produced by the converters of Jigang Group co. ltd, and study the feasibility of using the steel slag as base course material. Prepare cement stabilized steel slag specimens with different contents of cement mixed for the unconfined compressive strength test. Determine through test its strength after 7 days and 28 days and its water stability after 7 days’ soaking. Prepare in the same method of two different kinds of cement and coal ash stabilized specimens with different contents of coal ash mixed for the unconfined compressive strength test, to test its strength and water stability. The comparison on mechanical property with cement stabilized macadam indicates that the cement stabilized steel slag and cement with coal ash stabilized steel slag both have favorable mechanical property and water stability and the steel slag produced by the converters of Jigang Group co. ltd can be popularized for use as base course material.

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