scholarly journals Effects of Cement Content, Curing Period, Gradation, and Compaction Degree on Mechanical Behavior of Cement-Stabilized Crushed Gravel Produced via Vertical Vibration Test Method

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yingjun Jiang ◽  
Tian Tian ◽  
Changqing Deng ◽  
Kejia Yuan ◽  
Yong Yi
Keyword(s):  
Mechanical Strength ◽  
Cement Content ◽  
Prediction Equation ◽  
Core Sample ◽  
Vertical Vibration ◽  
Test Method ◽  
Strength Prediction ◽  
Vibration Test ◽  
Curing Period ◽  
Compaction Degree

In this paper, the reliability of vertical vibration test method (VVTM) was evaluated by comparing the changes in moisture content and gradation before and after forming the test piece by VVTM and static pressure method and the mechanical strength correlation between the laboratory compaction sample and the core sample in the field. The effects of cement content, curing period, gradation, and compaction degree on the unconfined compressive strength, splitting strength, and compressive rebound modulus of VVTM-compacted cement-stabilized crushed gravel (CSCG) were studied, and a mechanical strength prediction equation for VVTM-compacted CSCG was formulated. The results show that the correlation between the strength of the VVTM specimen and the field core sample can reach 92%; the mechanical strength of CSCG will increase with increase in the cement content, and when the cement content reaches approximately 4%, the increase in its mechanical strength will slow down; the mechanical strength of VVTM-compacted CSCG with different cement dosages and gradation types increased fast at 14 days of curing period and began to level off after 90 days. Compared with XM gradation, using GM gradation can improve the mechanical strength. Under different gradations and curing periods, the mechanical strength linearly increases with increase in the degree of compaction. The mechanical strength prediction equation has a high reliability; therefore, it can accurately predict the strength growth rules. Moreover, the degree of compaction increases by 1%, and the mechanical strength increases by approximately 10%.

scholarly journals Cement-Modified Loess Base for Intercity Railways: Mechanical Strength and Influencing Factors Based on the Vertical Vibration Compaction Method

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3643
Author(s):  
Yingjun Jiang ◽  
Qilong Li ◽  
Yong Yi ◽  
Kejia Yuan ◽  
Changqing Deng ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
High Speed ◽  
Cement Content ◽  
Vertical Vibration ◽  
Initial Growth ◽  
High Speed Railway ◽  
Growth Properties ◽  
Vibration Compaction ◽  
Growth Equations ◽  
Compaction Method

Cement-modified loess has been used in the recent construction of an intercity high-speed railway in Xi’an, China. This paper studies the mechanical strength of cement-modified loess (CML) compacted by the vertical vibration compaction method (VVCM). First, the reliability of VVCM in compacting CML is evaluated, and then the effects of cement content, compaction coefficient, and curing time on the mechanical strength of CML are analyzed, establishing a strength prediction model. The results show that the correlation of mechanical strength between the CML specimens prepared by VVCM in the laboratory and the core specimens collected on site is as high as 83.8%. The mechanical strength of CML initially show linear growth with increasing cement content and compaction coefficient. The initial growth in CML mechanical strength is followed by a later period, with mechanical strength growth slowing after 28 days. The mechanical strength growth properties of the CML can be accurately predicted via established strength growth equations. The results of this study can guide the design and construction of CML subgrade.

scholarly journals Comparison of Mechanical Properties of Cement-Stabilized Loess Produced Using Different Compaction Methods

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Yingjun Jiang ◽  
Kejia Yuan ◽  
Qilong Li ◽  
Changqing Deng ◽  
Yong Yi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Cement Content ◽  
Resilient Modulus ◽  
Great Influence ◽  
Field Measurements ◽  
Vertical Vibration ◽  
Dry Density ◽  
Curing Time ◽  
Compaction Method

Mechanical properties are important indexes to evaluate the improvement effect and engineering performance of cement-stabilized loess (CSL). This paper presents a comparison of the mechanical properties of CSL compacted using hammer quasi-static compaction method (QSCM) and vertical vibration compaction method (VVCM). The compaction properties, unconfined compressive strength (UCS), splitting strength (SPS), and resilient modulus (RM) of the laboratory-compacted CSL using VVCM and QSCM are tested and compared. Furthermore, the effects of compaction method, cement content, compaction coefficient, and curing time of the CSL specimens are investigated. In addition, field measurements are carried out to validate the laboratory investigations. The results show that the laboratory-compacted CSL using VVCM has a larger dry density and smaller optimum water content than that using QSCM. And the compaction method has a great influence on the mechanical strength of CSL. The UCS, SPS, and RM of the specimen produced using VVCM are averagely 1.17 times, 1.49 times, and 1.17 times that of CSL produced using QSCM, respectively, and the UCS, SPS, and RM of the specimens produced using these two methods increase linearly as the cement content and compaction coefficient increase, while the mechanical strength growth curve experiences three periods of increasing sharply, increasing slowly, and stabilizing with the curing time increased. Moreover, the results also show that the mechanical properties of laboratory-compacted CSL using VVCM have a better correlation of 83.8% with the field core samples.

Vibration Test Method of Aero-Engine 3D Printing Pre-Swirl Nozzle

2021 ◽  
Author(s):  
Yujie Zhao ◽  
Yeda Lian ◽  
Lei Li ◽  
Xu Gong ◽  
Xianghai Chai ◽  
...  
Keyword(s):  
3D Printing ◽  
Test Method ◽  
Vibration Test ◽  
Aero Engine

scholarly journals Investigation on cement-improved phyllite based on the vertical vibration compaction method

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247599
Author(s):  
Yingjun Jiang ◽  
Jiangtao Fan ◽  
Yong Yi ◽  
Tian Tian ◽  
Kejia Yuan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Static Pressure ◽  
Cement Content ◽  
Vertical Vibration ◽  
Pressure Method ◽  
Vibration Compaction ◽  
Modulus Of Resilience ◽  
Compaction Method

The vertical vibration compaction method (VVCM), heavy compaction method and static pressure method were used to form phyllite specimens with different degrees of weathering. The influence of cement content, compactness, and compaction method on the mechanical properties of phyllite was studied. The mechanical properties of phyllite was evaluated in terms of unconfined compressive strength (Rc) and modulus of resilience (Ec). Further, test roads were paved along an expressway in China to demonstrate the feasibility of the highly weathered phyllite improvement technology. Results show that unweathered phyllite can be used as subgrade filler. In spite of increasing compactness, phyllite with a higher degree of weathering cannot meet the requirements for subgrade filler. With increasing cement content, Rc and Ec of the improved phyllite increases linearly. Rc and Ec increase by at least 15% and 17%, respectively, for every 1% increase in cement content and by at least 10% and 6%, respectively, for every 1% increase in compactness. The higher the degree of weathering of phyllite, the greater the degree of improvement of its mechanical properties.

Sign in / Sign up

Export Citation Format

Share Document