Practical Approach to Criteria for the Use of Lime–Fly Ash Stabilization in Base Courses

2005 ◽  
Vol 1936 (1) ◽  
pp. 20-27 ◽  
Author(s):  
William F. Barstis ◽  
John Metcalf
Keyword(s):  
Fly Ash ◽  
Current Method ◽  
Visual Observation ◽  
Base Layer ◽  
Soil Base ◽  
Base Course Material ◽  
Stabilized Soil ◽  
Base Course ◽  
Additional Support

In October 2000 the Mississippi Department of Transportation (MDOT) initiated a study to evaluate the long-term performance of lime–fly ash (LFA) stabilized soil as a base course material. This study entailed performing falling weight deflectometer (FWD) tests on both newer and older pavements and coring pavement at each FWD location to observe the condition of the layers, to obtain pavement thicknesses, and to perform unconfined compressive strength (UCS) testing. Visual observation, backcalculated modulus, and in situ structural layer coefficient values showed that MDOT LFA-stabilized soil base courses have highly variable material properties and thicknesses. Recommendations were made to increase the average LFA material property values and to reduce the spread in these values by increasing the required compaction of the LFA-stabilized soil base layer to 100% standard Proctor effort, setting the required in situ Proctor UCS at 400 psi, and reducing variability by either improving the current method of field-mixed-in-place stabilization or requiring plant-mixed material with placement of the blended material via a paver. It is further recommended to increase the typical LFA-stabilized soil base layer design thickness from 6 to 8 in. and to use a 6-in. chemically stabilized subgrade layer to provide additional support to the pavement structure.

scholarly journals Ultimate Bearing Capacity of Stabilized Soil in Pavements

2020 ◽  
Vol 9 (5) ◽  
pp. 2349-2351
Keyword(s):  
Fly Ash ◽  
Bearing Capacity ◽  
Coal Ash ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Base Layer ◽  
Plate Load Test ◽  
Rubber Powder ◽  
Stone Dust ◽  
Stabilized Soil

This paper discusses the Ultimate Bearing Capacity of a stabilized soil by using the fly ash, stone dust and rubber powder for design of a pavement. This paper will help in utilization of locally available waste materials to reuse in the subbase and subgrade layers of pavement. Rubber powder is a waste byproduct generated from the recycling of tires, and is not so easy for degradable, and hence leads to release of harmful gases when it tends to burn. Stone dust is a locally available waste generated product from quarries. The generation of stone dust is increasing day to day in large quantity. The huge quantity of stone dust storage amount will affect the quality of soil. Fly ash is waste combusted coal ash powder generated from the steamers of coal boilers with the burning of fuel gases together. In the sub grade layer the soil is mixed in different proportions with stone dust for hard foundation. In the sub base layer the soil is stabilized with the combination of rubber powder and fly ash. When the rubber powder and fly ash, mixed with water for compaction generates a bond between the soil particles to settle the air fields. In this paper various percentages of rubber powder, stone dust and fly ash with different samples for pavement is layered, and after that plate load test is conducted upon it.

Resilient Properties and Fatigue Damage in Stabilized Recycled Aggregate Base Course Material

1998 ◽  
Vol 1611 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Khaled Sobhan ◽  
Raymond J. Krizek
Keyword(s):  
Elastic Modulus ◽  
Fly Ash ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Resilient Modulus ◽  
Recycled Aggregate ◽  
Fiber Reinforced ◽  
Base Course Material ◽  
Course Material ◽  
Base Course

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.

Study on Solidification Mechanism of Chloride Salt in Base Course Material of Cement-Fly-ash-Flushed-by-Seawater

2011 ◽  
Vol 236-238 ◽  
pp. 755-761
Author(s):  
Long Sheng Bao ◽  
Xiao Fang Zhang ◽  
Ling Yu ◽  
Guang Shan Zhu
Keyword(s):  
Fly Ash ◽  
Chloride Ions ◽  
Chloride Salt ◽  
Analysis Method ◽  
X Ray Diffraction ◽  
Base Course Material ◽  
Course Material ◽  
Base Course ◽  
Solidification Mechanism ◽  
Unconfined Strength

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.

Stabilization of fly ash and lime sludge composites: Assessment of its performance as base course material

2017 ◽  
Vol 17 (3) ◽  
pp. 475-485 ◽  
Author(s):  
Vaishali Sahu ◽  
Amit Srivastava ◽  
Anil Kumar Misra ◽  
Anil Kumar Sharma
Keyword(s):  
Fly Ash ◽  
Base Course Material ◽  
Course Material ◽  
Lime Sludge ◽  
Base Course

scholarly journals Evaluation of Cement and Bitumen Emulsion on Strength Characteristics of Native South African Granular Soil as Base Course Material

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Oladapo S Abiola ◽  
Reece Wilson ◽  
Anthony Barnard ◽  
Shaun Hattingh ◽  
William K Kupolati ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
South African ◽  
Unconfined Compressive Strength ◽  
Base Layer ◽  
Bitumen Emulsion ◽  
Base Course Material ◽  
Course Material ◽  
Indirect Tensile ◽  
Base Course

Pavement rehabilitation where the material in the existing pavement is recycled in-situ with bitumen will sustain the environment with conservation of natural aggregates, reduction in noise, dust emission and traffic disruption. This study investigate the effects of a native South African granular material stabilized with cement and bitumen emulsion as a base layer in pavement construction. The material stabilized with cement-bitumen emulsion (2-3%) was subjected to Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) tests for 1, 4, 7 and 28 days curing. The UCS and ITS requirement was evaluated with respect to a base layer for design traffic application of less than six million equivalent single axles. The results of UCS and ITS tests for the stabilized material showed improved strength and have the potential for use as a base course material for the design traffic. The result revealed that 2.5% cement and bitumen emulsion meets the minimum strength characteristics for the base layer. Relative to 2% cement and 2% bitumen emulsion, ITS obtained for 4 and 7 days of curing increased approximately by 24%, 41% and 24%, 53% respectively. Models for UCS in terms of ITS was developed for cement and bitumen emulsion which will make one test among the two sufficient to indicate the strength of cement and bitumen emulsion stabilized materials at the mix design level. Bitumen stabilization is a quick construction method, with lower cost than reconstruction and good for rehabilitation. Keywords— bitumen emulsion, cement, granular, indirect tensile strength unconfined compressive strength. 

Test on the Performance of Road Base-Course Made of Steel Slag and Fly Ash

2010 ◽  
Vol 168-170 ◽  
pp. 2078-2081
Author(s):  
Zhan You Yan ◽  
Yu Shu ◽  
Jian Qing Bu ◽  
Xiang Guo Li
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Resilient Modulus ◽  
Thermal Power ◽  
Steel Slag ◽  
Split Tensile Strength ◽  
The Road ◽  
Road Base ◽  
Base Course Material ◽  
Base Course

Fly-ash is an industrial waste burning pulverize coal boilers for thermal power plant and large enterprises, the steel slag is too a residue generated waste in steelmaking industrial processes, the average for every ton steel to produce half ton steel slag, steel slag and fly ash discharge amounts is very big, utilization ratio is very low. At present, a large number of steel slag is used of reclamation work, the remaining items is used rarely and large number is left storage. This paper is introduction steel slag and fly ash to do road base-course material, such can make good use of industry residue waste in large amount to reduce exploitation and cut down natural building stones, it is an application for ecological building materials again. Major study the steel slag and fly ash road features, these tests include materials compaction reality among them, mix design, unconfined compressive strength, split tensile strength, resilient modulus and other commonly used performance. Through comparative analysis, this two materials combination has good use of quality, it has greatly better than other materials such as lime-fly-ash stabilize crushed stone and lime-fly-ash soil and other materials. In particular, it has very good performance to reduce road base-course crack, the material has good resistance shrinkage and temperature shrinkage ability. Therefore, the combination of steel slag and fly ash can be done entirely road base-course and extend the road life.

scholarly journals Experimental Water Quality Analysis from the Use of High Sulfuric Fly Ash as Base Course Material for Road Building

2019 ◽  
Vol 9 (5) ◽  
pp. 4627-4630
Author(s):  
N. Viet Duc
Keyword(s):  
Water Quality ◽  
Fly Ash ◽  
Human Life ◽  
Quality Analysis ◽  
Arsenic Content ◽  
Road Building ◽  
Chemical Admixture ◽  
Base Course Material ◽  
Course Material ◽  
Base Course

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.

In-situ reaction between arsenic/selenium and minerals in fly ash at high temperature during blended coal combustion

2020 ◽  
Vol 48 (11) ◽  
pp. 1356-1364
Author(s):  
Jun HAN ◽  
Yang-shuo LIANG ◽  
Bo ZHAO ◽  
Zi-jiang XIONG ◽  
Lin-bo QIN ◽  
...  
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
Coal Combustion ◽  
In Situ Reaction ◽  
Blended Coal
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