Stabilizing Sandy Silt Soil with Fly-Ash Based RCA Geopolymer in Pavement Base Layers

Experimental studies were carried out on fly ashes from two Indian thermal power plants, namely Rajghat and Dadri, with the aim of improving the utilization of fly ash in geotechnical engineering applications. It was attempted to improve the engineering performance of fly ash by several means such as by mixing fly ash with soils, cement, and polyester fibers. The research program included the study of: a) physical properties, chemical composition and morphology of the fly ashes; b) compaction, strength, and permeability characteristics of the fly ashes and fly ash-soil mixtures; c) compaction and strength characteristics of fly ash-soil mixtures stabilized with fibers alone, with cement alone, and with both cement and fibers. Results showed that addition of fly ash to soils would result in lighter and stronger fills. Fiber inclusions increased the strength of fly ash-soil specimens significantly and altered their behaviour from brittle to ductile. Even small cement contents increased the strength of the fly ash-soil mixtures significantly. With higher cement contents of up to 18% it was possible to prepare fly ash-cement design mixes that satisfied the strength criteria for pavement base courses.

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Stabilization of Demolition Materials for Pavement Base/Subbase Applications Using Fly Ash and Slag Geopolymers: Laboratory Investigation

Journal of Materials in Civil Engineering ◽

10.1061/(asce)mt.1943-5533.0001526 ◽

2016 ◽

Vol 28 (7) ◽

pp. 04016033 ◽

Cited By ~ 61

Author(s):

Alireza Mohammadinia ◽

Arul Arulrajah ◽

Jay Sanjayan ◽

Mahdi M. Disfani ◽

Myint Win Bo ◽

...

Keyword(s):

Fly Ash ◽

Laboratory Investigation ◽

Pavement Base

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Microstructural Development of Stabilized Fly Ash as Pavement Base Material

Journal of Materials in Civil Engineering ◽

10.1061/(asce)0899-1561(2000)12:2(157) ◽

2000 ◽

Vol 12 (2) ◽

pp. 157-163 ◽

Cited By ~ 26

Author(s):

A. Hilmi Lav ◽

M. Aysen Lav

Keyword(s):

Fly Ash ◽

Base Material ◽

Microstructural Development ◽

Pavement Base

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Influence of SO3 Content on Drying Shrinkage Cracking Resistance of Cement-Fly Ash Stabilized Crushed-Stones

Materials Science Forum ◽

10.4028/www.scientific.net/msf.620-622.279 ◽

2009 ◽

Vol 620-622 ◽

pp. 279-282

Author(s):

Xiao Chen ◽

Ming Kai Zhou ◽

Zhi Yong Fan

Keyword(s):

Fly Ash ◽

Drying Shrinkage ◽

Cracking Resistance ◽

Shrinkage Cracking ◽

Pavement Base ◽

Suitable Scope

The cement-fly ash stabilized crushed-stones are prepared with different cements, which SO3 contents are 1.8%,2.6%,3.4%,4.2%,5.0%,5.8% and 8.8%，and their 28d splitting strengths, 28d resilient modulus’s, expansion -shrinkage and dry shrink anti cracking coefficients are studied. On these bases, the influence of SO3 content of cement on shrinkage cracking resistance is analyzed. The mechanism of compensating shrinkage by micro expansion in pavement base and the function of SO3 on cement-fly ash binder are also explored in paper. It is proved that the increase of SO3 content in a suitable scope (1.8%-5.8%) can improve the drying shrinkage cracking resistance of cement-fly ash stabilized crushed-stones when the content of fly ash is 10%。But the structure and the performance of materials will be destroyed if the SO3 content of cement increases excessively (>8.8%).

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Cement-Lime-Fly Ash Bound Macadam Pavement Base Material with Enhanced Early-Age Strength and Suppressed Drying Shrinkage via Incorporation of Slag and Gypsum

Advances in Civil Engineering ◽

10.1155/2019/8198021 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Cheng Ju ◽

Yushi Liu ◽

Zhenyun Yu ◽

Yingzi Yang

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Base Material ◽

Drying Shrinkage ◽

Test Method ◽

Early Age ◽

Optimal Mix ◽

Orthogonal Test Method ◽

Pavement Base ◽

Compressive And Flexural Strengths

In this study, a novel cement-lime-fly ash bound macadam (CLFBM) as pavement base material was designed by incorporating Portland cement, dihydrate gypsum (CaSO4·2H2O), and ground granulated blast furnace slag (GGBS) into the lime-fly ash bound macadam (LFBM) for the purpose of the early opening to traffic. The multifactors orthogonal test method was used to evaluate the effects of Portland cement, dihydrate gypsum, and GGBS on the early-age strength of CLFBM. Moreover, the compressive and flexural strengths at 28 days as well as the drying shrinkage development in 56 days were investigated. By conducting the comprehensive analysis for the better mechanical properties and the lowest drying shrinkage, Portland cement : dihydrate gypsum : lime : fly ash : GGBS : gravels = 2 : 1 : 6 : 5.6 : 8.4 : 80 is determined as the optimal mix proportion of CLFBM. In addition, scanning electron microscope (SEM) results confirmed the formation of a large number of ettringite and C-S-H gels, providing a powerful support for the enhanced early-age strength and suppressed drying shrinkage of CLFBM.

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Influence of Some Additives on the Properties of OPC Solidified Sandy Silt

Applied Sciences ◽

10.3390/app11167252 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7252

Author(s):

Dazhi Wu ◽

Keyu Chen ◽

Zilong Zhang ◽

Lifu Chang

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Resilient Modulus ◽

Solidification Process ◽

Cementitious Materials ◽

X Ray Diffraction ◽

Clay Particles ◽

Sandy Silt ◽

Mass Fractions ◽

Bonding Properties

The ordinary Portland cement (OPC)-based solidification process is used extensively to reinforce soils due to its available and good bonding properties. Alternative products are used in cementitious materials to enhance the strength and to reduce OPC consumption. In this study, the effect of additive type and mass fraction on the microstructure and mechanical properties of solidified sandy silt are investigated. There are four types of additives (gypsum, lime, clay particles, and fly ash) at mass fractions of 2, 3, and 4% that are considered in order to study their mechanical properties (unconfined compression, indirect tensile, flexural strength, and compressive resilient modulus) at 7, 14, 28, 60, and 90 days. The optimal contents of additive gypsum, clay particles, and fly ash are determined to be 2%, 4%, and 4%, respectively. Such improvement of additive-modified OPC solidified sandy silt is due to the formation of the crystalline compound or the gradation composition improvement via field emission scanning electron and X-ray diffraction analysis.

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Seasonal Performance Evaluation of Pavement Base Using Recycled Materials

Sustainability ◽

10.3390/su132212714 ◽

2021 ◽

Vol 13 (22) ◽

pp. 12714

Author(s):

Yang Zhang ◽

Bora Cetin ◽

Tuncer B. Edil

Keyword(s):

Fly Ash ◽

Recycled Concrete ◽

Ride Quality ◽

Concrete Aggregate ◽

Traffic Loading ◽

Pavement Base ◽

Natural Aggregates ◽

Long Term Performance ◽

Term Performance

Using recycled pavement materials to construct new pavement base is currently an important construction strategy bringing improved sustainability. This study investigates the long-term performance of pavement bases constructed with recycled concrete aggregate (RCA), reclaimed asphalt pavement (RAP), and blends with natural aggregates in a seasonal frost region. The stabilization effect of fly ash on RAP was studied as well. In situ falling weight deflectometer (FWD) tests were routinely conducted to provide seasonal deflection data, which were used to back-calculate the layer modulus. Seasonal changes in the base layer modulus along with the pavement ride quality were monitored. One of the two lanes at the test sections was consistently subjected to traffic loading, whereas the other one was not. Findings from this field research indicated that after undergoing over 8 years of naturally seasonal freeze-thaw conditions, 100% RCA, 50% RCA, plus 50% natural aggregates, and 100% RAP, presented improved performance over 100% natural aggregates. However, 50% RAP blended with 50% natural aggregates performed comparably to natural aggregates only, and fly ash did not provide considerable improvement on the long-term performance of 50% RAP plus 50% natural aggregate base. Seasonal climatic variations turned out to affect pavement performance more critically than traffic loading.

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