scholarly journals STABILIZATION OF MARGINAL CRUSHED ROCK USING CEMENT AND FLY ASH AS A GREEN BASE COURSE MATERIAL

2021 ◽  
Vol 20 (77) ◽  
Author(s):  
Mathagul Metham
Author(s):  
Khaled Sobhan ◽  
Raymond J. Krizek

A stabilized fiber-reinforced base course material composed largely of recycled concrete aggregate with small amounts of portland cement and fly ash was subjected to repeated flexural loading to evaluate its resilient properties and progressive accumulation of fatigue damage. Cyclic load-deformation data were recorded continuously during the entire fatigue life until fracture to determine ( a) the magnitude and variation of cumulative plastic strain and dynamic elastic modulus as a function of the number of loading cycles, ( b) a range for the resilient modulus, and ( c) the effect of fiber inclusions on the dynamic material properties and rate of damage accumulation. The extent of fatigue damage was calculated as a fatigue damage index, which is based on the cumulative energy dissipated (absorbed) during cyclic loading. All beam specimens used in this experimental program contained (by weight) 4 percent cement, 4 percent fly ash, and 92 percent recycled aggregate; the fiber-reinforced specimens contained an additional 4 percent (by weight) hooked-end steel fibers. Results show that the resilient modulus in flexure varies between about 2.75 GPa (400,000 lbf/in2.) and 10.4 GPa (1.5 million lbf/in.2) and the degradation of the dynamic elastic modulus does not exceed 25 percent of the initial modulus. Miner’s Rule of linear summation of damage is applicable to unreinforced material but not to fiber-reinforced material. In general, a modest amount of reinforcing fibers was very effective in retarding the rate of fatigue damage accumulation in this lean cementitious composite.


Author(s):  
Thomas C. Kinney ◽  
Danielle Stone ◽  
John Schuler

A model road was constructed in a laboratory. The road consisted of asphalt over a crushed rock base and a silty sand and gravel subbase. The silty sand and gravel were placed in a very loose state to simulate a thaw-weakened, poor-quality subbase. The water table was kept at 152 mm (6 in.) below the bottom of the asphalt. The model road was divided into three sections. A geogrid was installed at the bottom of the base course material in two of the test sections, and the third was left as a control section. A falling weight deflectometer was used to measure the dynamic response of the pavement structure. The traffic benefit ratio is defined as the expected life (equivalent single-axle loads) of one section divided by the expected life of another section. The Alaska Department of Transportation and Public Facilities asphalt pavement design procedure and the NCHRP pavement design procedure were used to compare the test sections. The results from the two procedures were very similar. By using either procedure, the life of the pavement with respect to reinforcement was on the order of 2 to 4, depending on the type of grid and the depth of base course material.


2019 ◽  
Vol 10 (2) ◽  
pp. 101-112
Author(s):  
M. Seyfe ◽  
A. Geremew

Cinder gravels are pyroclastic materials associated with recent volcanic activity which occur in characteristically straight sided cone shaped hills. The aim of this study was to use this marginal material which is abundantly available in many parts of Ethiopia by modifying their properties through mechanical blending and chemical stabilization. Results of physical and mechanical test conducted on cinder gravel samples prove their marginality to be used as base course materials especially for highly trafficked roads. An experimental investigation were carried by blending cinder gravels with conventional crushed stone bases course material, Crushed Stone Aggregate (CSA), in proportions of cinder/ Crushed Stone Aggregate (CSA) (10/90, 20/80, 30/70, 40/60 and 50/50) and treating with 6. 8 and 10% of cement. According to results of sieve analysis, Aggregate crushing value (ACV), flakiness index and California Bearing Ratio (CBR), 30% of Crushed Stone Aggregate (CSA) can be replaced by cinder gravels for use as Fresh, crushed rock (GB1) material and for cement treated cinder gravels adding 6% and 8% cement make them suitable for use as Stabilized base course (CB2) and (CB1) base course materials respectively, referring to their 14 day compressive strength as determined by Unified compressive strength test(UCS) test.


2011 ◽  
Vol 236-238 ◽  
pp. 755-761
Author(s):  
Long Sheng Bao ◽  
Xiao Fang Zhang ◽  
Ling Yu ◽  
Guang Shan Zhu

Through analyzing the influence of different slat content on the microstructure of cement and fly-ash-flushed-by-seawater binder, the solidification mechanism of salt added cement and fly-ash-flushed-by-seawater binder is investigated. The Scanning Electron Microscope test, X-Ray diffraction and theoretical analysis method are adopted to study the performance and the microstructure of cement and fly-ash-flushed-by-seawater, and to analyze the solidification mechanism of chloride in the mixture. When content of the chloride ions is added to the cement and fly-ash-flushed-by-seawater binder, a new kind of crystal-Friedel can be generated in the age of 7d and 28d. According to the unconfined strength test on the specimens which contain 0.5% chloride ions, the strength is high in 7d, highest in 28d. The chloride ions of the fly-ash-flushed-by-seawater can be solidified in the cement and fly-ash-flushed-by-seawater binder, which can increase the strength of the binder.


2017 ◽  
Vol 17 (3) ◽  
pp. 475-485 ◽  
Author(s):  
Vaishali Sahu ◽  
Amit Srivastava ◽  
Anil Kumar Misra ◽  
Anil Kumar Sharma

2019 ◽  
Vol 9 (5) ◽  
pp. 4627-4630
Author(s):  
N. Viet Duc

Water quality directly influences human life. Drinking water contamination can result in severe health problems. This paper deals with the analysis of water specimens from submergence of material containing high sulfuric fly ash as base course material for road building. The specimens were obtained from real road testing. Results showed that for the material that used fly ash and chemical admixture, water quality was suitable for drinking in accordance with the standard parameters prescribed by the Vietnam Ministry of Health, while for the material that used the same fly ash without chemical admixture, the total arsenic content was eight times higher than that of the former. Thus, if one desires to utilize fly ash with high sulfur as base course material for road building, it needs to be used in combination with appropriate chemical admixture, so that it would not affect ground water quality.


Author(s):  
Shinichiro KAWABATA ◽  
Tatsuya ISHIKAWA ◽  
Takumi MURAYAMA ◽  
Shuichi KAMEYAMA

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