Research about Different Molding Methods’ Effect on the Resistance against Frost and Shrinkage of Cement Stabilized Gravel

2011 ◽  
Vol 90-93 ◽  
pp. 317-322
Author(s):  
Hai Long Liu ◽  
Pei Feng Cheng
Keyword(s):  
Static Pressure ◽  
Vibration Method ◽  
The Road ◽  
Pressure Method ◽  
Field Control ◽  
Vibration Compaction ◽  
Dry Shrinkage ◽  
Resistance Performance ◽  
Molding Methods ◽  
Better Than

Through the test research of the two different molding methods of vibration and static pressure, including the analysis of traditional heavy compaction and the new vibration compaction, we could see that the result of the vibration could satisfied the field construction. Analysis of mechanical property was 7d unconfined compressive strength, at the same dose of cement, the strength of vibration was higher than the static pressure method’s and it was more rational and effective for the field control of the construction. Evaluation of water stability was up to the 28d and 5 times freezing-thawing tests, and the resistance ability against frost of vibration was better than the static pressure method. So adopting the vibration method could improve the resistance performance against frost of the road in northeast region of freezing-thawing in spring. From the 7d dry shrinkage test we got that the adopting the vibration method the resistance performance of dry shrinkage was much better and could improve the resistance against shrinkage of the road.

Experimental Research the Pavement Performance on Chloride-Based Weak Saline Soil

2012 ◽  
Vol 512-515 ◽  
pp. 3017-3023
Author(s):  
Jun Yong Liu ◽  
Liu Jun Zhang ◽  
Li Hua Yin
Keyword(s):  
Comparative Study ◽  
Experimental Research ◽  
Static Pressure ◽  
Saline Soil ◽  
Pavement Performance ◽  
Test Results ◽  
Vibration Method ◽  
The Road ◽  
Pressure Method

The pavement performance (CBR and modulus of resilient) of the weak chloride-based saline soil was studied by experiment. Samples were made through the static pressure method and vibration method. The test results for the samples under the conditions of non-soaking and soaking made a comparative study. The weak saline soil was analyzed as embankment feasibility. The results showed that: the pavement performance of samples made by vibration method was superior to that of static pressure method; the CBR value and modulus of resilient of samples could meet standard requirements when degree of compaction met the standard requirements. Weak chloride-based saline soil proved to be the road embankment fillers.

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.

Comparative Research on Pavement Performance of Cement Stabilized Macadam Base in Different Molding Methods

2014 ◽  
Vol 505-506 ◽  
pp. 210-214 ◽  
Author(s):  
Bo Li ◽  
Jian Xuan Liu ◽  
Xiao Hui Li
Keyword(s):  
Comparative Research ◽  
Static Pressure ◽  
Drying Shrinkage ◽  
Pavement Performance ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Actual Degree ◽  
Actual Field ◽  
Molding Methods ◽  
Better Than

The indoor molding methods don't match the actual degree of compaction, which will cause the compaction over one hundred degrees and the more reflective cracks of the cement stabilized macadam base. In order to prevent this kind of phenomenon, a series tests on two kinds different molding methods were conducted. It contained maximum dry density, UCS,drying shrinkage performance and impact of aggregates performance .The results show that the dry density and UCS(unconfined compressive strength) of vibration molding are greater than isostatic pressing method's, the drying shrinkage performance of vibration molding is better than static pressure molding's. The vibration molding has less affected for the aggregate performance. It is more similar to the actual field.

Research of Water Damage Resistance Performance of CAM in Low Temperature Condition

2013 ◽  
Vol 723 ◽  
pp. 157-162
Author(s):  
Jian Li ◽  
Qu Chao ◽  
He Ping
Keyword(s):  
Low Temperature ◽  
Atmospheric Pressure ◽  
Asphalt Pavement ◽  
Natural World ◽  
Chloride Salt ◽  
The Road ◽  
Normal Atmospheric Pressure ◽  
Water Damage ◽  
Resistance Performance ◽  
Complex Polymer

Under normal atmospheric pressure conditions, volume suddenly increases about 11% when the water freezes and decreased when the ice melts. The pressure can reach up to 2500 times of atmospheric pressure in the closed space when the water freezing. This is a very important characteristic of the natural world and the industrial. In low temperature condition, the snow on the pavement is easy to melt and freeze, and it will affect the road safety, increase the cracking of the road and accelerate asphalt pavement water damage. Bitumen is a mixture consisting of some extremely complex polymer hydrocarbons and hydrocarbon derivatives of non-metallic (oxygen, sulfur, nitrogen). Deicing salt is used to prevent freezing in that area, chloride salt is its main ingredient. When the water melting point reduced, it is not easy to icing but to penetrate the asphalt pavement. If the temperature is continued to reduce, salt solution will still freezing. At last, the pavement will form water damage in repeated freeze-thaw cycles conditions.

scholarly journals Tribological Performance of CF‐PEEK Sliding Against 17‐4PH Stainless Steel with Various Cermet Coatings for Water Hydraulic Piston Pump Application

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 436 ◽  
Author(s):  
Nie ◽  
Lou ◽  
Ji ◽  
Yin
Keyword(s):  
Stainless Steel ◽  
Test Bench ◽  
Ring Test ◽  
High Rotational Speed ◽  
Cermet Coatings ◽  
Tribological Behaviors ◽  
Peek Composite ◽  
Water Hydraulic ◽  
Resistance Performance ◽  
Better Than

To improve the abrasion resistance performance of the critical tribopairs within water hydraulic piston pumps, tribological characteristics of the stainless steel 17‐4PH and 17‐4PH coated with Cr3C2‐NiCr, WC‐10Co‐4Cr, Cr2O3 and Al2O3‐13%TiO2 sliding against carbon fiber reinforced polyetheretherketone (CF‐PEEK) composite under water‐lubricated condition were experimentally studied using a pin‐on‐ring test bench with different working conditions. It has been demonstrated by the experimental results that the tribological behaviors of CF‐PEEK/cermet coatings tribipairs were better than that of CF‐PEEK/17‐4PH tribopair under water lubrication. However, the Cr3C2‐NiCr coating could be damaged under high rotational speed. Due to the reaction film produced by the Al2O3‐13%TiO2 and water, the CF‐PEEK/Al2O3‐13%TiO2 material combination exhibits more excellent tribological behaviors than other tribopairs lubricated with water, and could preferentially be used in water hydraulic piston pumps.

scholarly journals Effect of superabsorbent polymer on mechanical properties of cement stabilized base and its mechanism

2020 ◽  
Vol 2 (1) ◽  
pp. 58-68
Author(s):  
Yongsheng Guan ◽  
Zhixiang Zhang ◽  
Xiaorui Zhang ◽  
Junqing Zhu ◽  
Wen Zhou ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Static Pressure ◽  
Mercury Intrusion Porosimetry ◽  
Drying Shrinkage ◽  
Internal Curing ◽  
Hydration Products ◽  
Mercury Intrusion ◽  
Dry Shrinkage ◽  
Strength Improvement ◽  
Cement Stabilized Base

Abstract Superabsorbent polymers (SAPs) are cross-linked polymers that can absorb and retain large amounts of water. In recent years, a growing interest was seen in applying SAPs in concrete to improve its performance due to its efficiency in mitigating shrinkage. This paper presents findings in a study on effect of SAPs on performance of cement-treated base (CTB), using the experience of internal curing of concrete. CTB specimens with and without SAPs were prepared and tested in the laboratory. Tests conducted include mechanical property testing, dry shrinkage testing, differential thermal analysis, mercury intrusion porosimetry and scanning electron microscope testing. It was found that 7-day and 28-day unconfined compressive strength of CTB specimens with SAPs was higher than regular CTB specimens. 28d compressive strength of CTB specimens with SAPs made by Static pressure method was 5.87 MPa, which is 27% higher than that of regular CTB specimens. Drying shrinkage of CTB specimens with SAPs was decreased by 52.5% comparing with regular CTB specimens. Through the microstructure analysis it was found that CTB specimens with SAPs could produce more hydration products, which is also the reason for the strength improvement.

Analyzing Relationship between the Performance of the Fan and the Area of the Porous Thin Plate

2014 ◽  
Vol 488-489 ◽  
pp. 901-904
Author(s):  
Shu Lung Wang ◽  
Yueh Hua Wang
Keyword(s):  
Thin Plate ◽  
Static Pressure ◽  
Air Flow ◽  
Main Factors ◽  
The Difference ◽  
Better Than

The purpose of this research is to study the performance of axial fanof the porous thin plate. First, the area of the holes of the porous thin plate is changed to estimate the influence of the porous thin plate on the performance of the fan. This study is conducted by simulations and experiments to find out the factors that will impact the performance of the fan. The results show that if the area rate of the porous thin plate and the fan is smaller, the difference of the simulations and experiments will become greater. When the area rate is more than 80%, the difference of the simulations and experiments will turn to be 10% lower. The results of experiments show that the fan size and fan thickness are the two main factors that produce the influence on the porous thin plate. If the thickness of the bar of the porous thin plate is 2.0mm, the performance of the fan loss would be the smallest. As to the assembly position of the porous thin plate, unilateral assembly makes the performance of the fan better than bilateral assembly. This is in relation to the area size of the porous thin plate. Fan tray is bilateral assembled. The performance of the fan tray can be improved in the following two ways. To use the thicker fan as the static pressure is greater, or to use the fan with lower air flow as the loss will be lesser.

Effect of Geometry on the Performance of Radial Vaneless Diffusers

1987 ◽  
Vol 109 (4) ◽  
pp. 550-556 ◽  
Author(s):  
Yingkang Zhu ◽  
S. A. Sjolander
Keyword(s):  
Static Pressure ◽  
Pressure Rise ◽  
Aerodynamic Characteristics ◽  
Pressure Recovery ◽  
Flow Uniformity ◽  
Flow Rates ◽  
Convergence Results ◽  
Expected Performance ◽  
Vaneless Diffusers ◽  
Better Than

The paper presents measurements of the steady aerodynamic characteristics of a series of five radial vaneless diffusers with walls varying from mildly divergent to strongly convergent. The static pressure recovery was determined and the flow was traversed at the inlet and the outlet of the diffuser for a broad range of flow rates in each case. It was found that wall convergence results in a negative (stabilizing) slope in the pressure rise curve for the diffuser. Furthermore, at high flow rates convergence was found to reduce the pressure recovery far less than one would expect and at intermediate flow rates convergence actually improved the pressure recovery. The better-than-expected performance is thought to be closely related to the observed improvement in the flow uniformity at the diffuser outlet when convergent walls are used.

Experimental Study on Foamed Asphalt Warm Mix Technology

2014 ◽  
Vol 919-921 ◽  
pp. 1110-1114
Author(s):  
Ying Biao Wu ◽  
Jin Jin Shi ◽  
Chen Fang Yang ◽  
Sheng Xia Song
Keyword(s):  
Evaluation Method ◽  
Asphalt Mixture ◽  
The Road ◽  
Foamed Asphalt ◽  
Outdoor Experiment ◽  
Road Performance ◽  
Cold Recycling ◽  
Lower Temperature ◽  
Specification Requirement ◽  
Better Than

Usually, foamed asphalt as cold recycling mixture binder, study on foamed asphalt warm mix technology was limited in China. Aimed at the asphalt foaming characteristic, the paper put forward the best asphalt foaming condition and carried out indoor and outdoor experiment to study the road performance of warm mixed asphalt mixture. The paper proposed the maturation curing time concept and its evaluation method. Results indicated that the warm mixed asphalt mixtures road performance can meet the HMA specification requirement in a lower temperature of construction, and low-temperature crack resistance was better than the tradition hot mix asphalt mixture so the warm mix foamed mixture has a remarkable economic and society benefit.

Study on Sulfate-Attack of Slag-Based Geopolymer Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 142-146
Author(s):  
Qing Wang ◽  
Zhao Yang Ding ◽  
Lin Li ◽  
Jing Da ◽  
Zhi Tong Sui
Keyword(s):  
Mass Loss ◽  
Water Glass ◽  
Linear Expansion ◽  
Mass Loss Rate ◽  
Expansion Rate ◽  
Geopolymer Concrete ◽  
Commercial Applications ◽  
Resistance Performance ◽  
Better Than

Geopolymer has been attracted world attention as a potentially revolutionary material that is one of the ideal substitutes of portland cement. Fundamental studies on geopolymer are increasing rapidly because of its potential commercial applications. However, little work has been done on its erosion resistance of sulfate. In this paper, slag and metakaolin as source materials, different modules of water-glass as activator were used to prepare slag-based geopolymer which was then prepared to make slag-based geopolymer concrete. Linear expansion rate and mass loss of concrete were used as indicators to explore different erosion rules of slag-based geopolymer concrete which was long-term immersed in the 5% ( by mass ) Na2SO4 solution. Comparative experiments were also done between slag-based geopolymer concrete and ordinary cement concrete. The results showed that geopolymer concrete had excellent sulfate resistance performance, linear expansion rate and mass loss rate of geopolymer were 0.024% and 0.58% respectively at the soaking age of 49d as the water glass modulus was 1.4 and the water-glass content was 4%. It was also found that the anti-sulfate ability of geopolymer concrete is much better than that of ordinary concrete with the same strength grade.

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