scholarly journals Role of Fly Ash on Strength Properties of Rejuvenated Soil Cement for Pavement Materials

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Prinya Chindaprasirt ◽  
Apichit Kampala ◽  
Pattawitchaya Daprom ◽  
Peerapong Jitsangiam ◽  
Suksun Horpibulsuk

Abstract Stabilization with cement is the most commonly used technique for the improvement of soil physical, mechanical, and engineering properties. This research reported on the properties of the rejuvenation for recycled soil cement with incorporation of fly ash (FA). The study showed that the specific gravity of Rejuvenated Soil Cement (RSC) decreased with increasing FA. The free swell ratio and linear shrinkage of RSC were significantly decreased with the increase in FA. The maximum dry unit weight of RSC increased with increasing FA up to the optimum FA content of 20 – 25 %. The optimum water content in compaction was relatively constant with the increase in FA. Particularly, the strength improvement in active zone of FA-RSC was influenced by several factors viz., compaction, packing, rehydration, and pozzolanic reaction. As a result, the unconfined compressive strength (UCS) of RSC increased with increase in FA and curing time. This research clearly showed that the rejuvenation of soil-cement with FA as additive was successful. It was also shown that the normalized UCSs of RSC at various curing times could be used to predict the UCSs at 7 and 28 days.

Author(s):  
Prerna Priya ◽  
Ran Vijay Singh

Expansive Black cotton clay soils are widely distributed worldwide, and are a significant damage to infrastructure and buildigs.It is a common practice around the world to stabilize black cotton soil using fly ash to improve the strength of stabilized sub- base and sub grade soil. Soil stabilization is the improvement of strength or bearing capacity of soil by controlled compaction, proportioning or addition of suitable admixtures or stabilizers. The Black cotton soils are extremely hard when dry, but lose its strength fully when in wet condition. In monsoon they guzzle water and swell and in summer they shrink on evaporation of water from there. Because of its high Swelling and shrinkage characteristics the black cotton soils has been a challenge to the highway engineers.So in this research paper fly ash has been used to improve the various strength properties of natural black cotton soil.The objective of this research paper is to improve the engineering properties of black cotton soil by adding different percentage of fly ash by the weight of soil and make it suitable for construction. A series of standard Proctor tests (for calculation of MDD and OMC) and California Bearing Ratio (C.B.R) tests are conducted on both raw Black cotton soil and mixed soil with different percentages of fly ash (5%, 10%, 20%, 30%) by weight. A comparison between properties of raw black cotton soil, black cotton soil mixed with fly ash are performed .It is found that the properties of black cotton soil mixed with fly ash are suitably enhanced.


2008 ◽  
Vol 45 (6) ◽  
pp. 877-887 ◽  
Author(s):  
Osman Sivrikaya ◽  
Ergun Togrol ◽  
Cafer Kayadelen

For successful designs of geotechnical structures, rational determination of the engineering properties of soils is an important process. In this context, compaction parameters, maximum dry unit weight (γdmax), and optimum water content (wopt) are required to be determined at various compaction energies. This paper proposes correlation equations that relate γdmax and wopt obtained from standard Proctor (SP) and modified Proctor (MP) tests to the index properties. To develop accurate relations, the data collected from the literature and the authors’ own database have been used. It has been found that while wopt has the best correlation with plastic limit (wp), γdmax can be estimated more accurately from wopt than it can from wp. In addition, the empirical methods including compaction energy (E) are described for estimating wopt and γdmax of fine-grained soils. The variables of the developed models for wopt and γdmax are wp, E, and wopt. It has been shown that the proposed correlations including the compaction energy will be useful for a preliminary design of a project where there is a financial constraint and limited time.


2012 ◽  
Vol 488-489 ◽  
pp. 1553-1557 ◽  
Author(s):  
Fahad Irfan Siddiqui ◽  
Syed Baharom Azahar Bin Syed Osman

Precise determination of engineering properties of soil is essential for proper design and successful construction of any structure. The conventional methods for determination of engineering properties are invasive, costly and time-consuming. Electrical resistivity survey is an attractive tool for delineating subsurface properties without soil disturbance. Reliable correlations between electrical resistivity and other soil properties will enable us to characterize the subsurface soil without borehole sampling. This paper presents the preliminary results of an ongoing research on correlations of electrical resistivity with strength properties of soil. Soil investigations, field electrical resistivity survey (VES) and laboratory electrical resistivity measurements were conducted. From the data analysis, significant correlations have been obtained between resistivity and moisture content and angle of internal friction. Weaker correlations have been observed for cohesion and unit weight of soil.


2020 ◽  
Vol 5 (1) ◽  
pp. 97-104
Author(s):  
M Umar ◽  
H. M. Alhassan

Two laterites samples known for their deficiency in road construction were used to assess the efficacy of Class C fly ash in improving their engineering properties. The two samples were taken from Danbare and Dausayi localities within Kano Metropolis and the fly ash was sourced from the Nigerian Coal Corporation, Enugu. Preliminary tests on the two samples confirmed their deficiency for use in road construction. The processed fly ash was blended with the laterite samples at 0, 3, 6, 9, 12, 15 and 18%. Hence, the treated soil samples were tested for plasticity, compaction and strength properties. Results obtained revealed reduction in plasticity properties as the fly ash contents increased. Similarly, Maximum Dry Density (MDD) decreased as the fly ash content increased while the Optimum Moisture Content (OMC) of the treated soils increased for the two samples. Peak CBR values of 16 and 35% were obtained at 9 and 15% fly ash contents for samples 1 and 2, respectively. The unconfined compression tests showed considerable improvement in strength properties higher than the values of the natural soils. The peak 7 days strength of 630 and 1410 kN/m2 were observed at 12% and 15% fly ash content for samples 1 and 2, respectively.


2014 ◽  
Vol 22 (4) ◽  
pp. 35-44 ◽  
Author(s):  
Sujeet Kumar ◽  
Rakesh Kumar Dutta ◽  
Bijayananda Mohanty

Abstract Engineering properties such as compaction, unconfined compressive strength, consistency limits, percentage swell, free swell index, the California bearing ratio and the consolidation of bentonite stabilized with lime and phosphogypsum are presented in this paper. The content of the lime and phosphogypsum varied from 0 to 10 %. The results reveal that the dry unit weight and optimum moisture content of bentonite + 8 % lime increased with the addition of 8 % phosphogypsum. The percentage of swell increased and the free swell index decreased with the addition of 8 % phosphogypsum to the bentonite + 8 % lime mix. The unconfined compressive strength of the bentonite + 8 % lime increased with the addition of 8 % phosphogypsum as well as an increase in the curing period up to 14 days. The liquid limit and plastic limit of the bentonite + 8 % lime increased, whereas the plasticity index remained constant with the addition of 8 % phosphogypsum. The California bearing ratio, modulus of subgrade reaction, and secant modulus increased for the bentonite stabilized with lime and phosphogypsum. The coefficient of the consolidation of the bentonite increased with the addition of 8 % lime and no change with the addition of 8 % phosphogypsum.


2021 ◽  
Vol 5 (1) ◽  
pp. 89-102
Author(s):  
Fuad Harwadi ◽  
Sepri Rantesalu ◽  
Nofrizal Nofrizal

Expansive soil is one of the problematic soils for civil engineering construction. The high swelling-shrinkage nature results in deformations that can damage the construction on it, therefore it is necessary to make improvements in expansive  soil. One of the most widely used methods of improving expansive soil is stabilization using chemical additives. In this research using coal waste material (fly ash) as stabilizer from PLTU Sekayan in Kaltara Province, so it can be said as environmentally friendly stabilization. The research objective was to determine changes in engineering behavior of expansive soil through compaction tests and CBR. The test results will be displayed in graphical form, namely by comparing the expansive soil that has not been stabilized (initial conditions) and the expansive soil that has been stabilized with fly ash at mixed variations of 20%, 30% and 40%, and has passed the curing period for 5, 15, and 30 days. From this research, it was found that the addition of a stabilizer (fly ash) could improve its engineering properties, and the optimum results were obtained at the addition of 40% fly ash and after 30 days of curing time. From the compaction test, it was found that the volume weight of dry soil (γdry) increased by 14.05% from 1.21 gr/cm3 to 1.38 gr/cm3 and the optimum water content (wopt) decreased by 38.12% from 31.19% to 19,3%. From CBR testing in the laboratory, there was a very large increase in the value of CBRDesign, namely 2192% from 0.72% to 16.5%


2011 ◽  
Vol 117-119 ◽  
pp. 1352-1357 ◽  
Author(s):  
Weerapol Namboonruang ◽  
Rattanakorn Rawangkul ◽  
Wanchai Yodsudjai

The development of new alternative type of fly ash bricks using the locally available local soil from Ratchaburi province were mixed with fly ash from Kanchanaburi province, where both sources in western of Thailand, is the main purpose of this study. These are compared to the ratchaburi local soil cement bricks without the mixing of western fly ash in different proportions. It is concluded that the addition of western fly ash reduces the thermal conductivity. The compressive and flexural strength decrease when the ratio of western fly ash is more than 30 percentages. However, considering the various factors it can be concluded that appropriate ingredient toward producing the good commercial western fly ash bricks is 5 percentages of portland cement and 30 percentages of western fly ash by weight basis of ratchaburi local soil. The compositions of western fly ash at more than 25 percentages by weight basis of ratchaburi local soil and since up to 14 days of curing time are proved to be economical mixtures for load bearing panels or brick type structural elements according to the Thai Industrial Standard for structural clay load-bearing tile.


2011 ◽  
Vol 6 (2) ◽  
pp. 88-106 ◽  
Author(s):  
Quinn M Pullen ◽  
Todd V Scholz

Cob is an earthen building material comprised of sand, clay, straw, and water used for millennia to construct dwellings. Although cob construction largely died out during the nineteenth century, it is experiencing a revival in England and the Pacific Northwest of the United States. Little scientific research has investigated the engineering properties of cob, knowledge of which is important for modern-day design practices and code requirements. Researchers at Oregon State University investigated six different Oregon cob mixtures using a series of standard soils and concrete tests adapted for this material. The objectives were to characterize the constituents, to establish estimates for the magnitude of, and degree of variability in, the mixture properties, and to develop correlations between the engineering properties and mixture composition. Results indicated low to moderate variation in basic mixture properties (i.e., unit weight, moisture content, and sand equivalent), moderate variation in strength properties, and high variation in the elastic modulus. Several reasonable correlations were found between shrinkage, compressive strength, elastic modulus, and sand equivalent and between flexural strength and fiber tensile strength.


J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 223-232
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán

Ground coal bottom ash is considered a novel material when used in common cement production as a blended cement. This new application must be evaluated by means of the study of its pozzolanic properties. Coal bottom ash, in some countries, is being used as a replacement for natural sand, but in some others, it is disposed of in a landfill, leading thus to environmental problems. The pozzolanic properties of ground coal bottom ash and coal fly ash cements were investigated in order to assess their pozzolanic performance. Proportions of coal fly ash and ground coal bottom ash in the mixes were 100:0, 90:10, 80:20, 50:50, 0:100. Next, multicomponent cements were formulated using 10%, 25% or 35% of ashes. In general, the pozzolanic performance of the ground coal bottom ash is quite similar to that of the coal fly ash. As expected, the pozzolanic reaction of both of them proceeds slowly at early ages, but the reaction rate increases over time. Ground coal bottom ash is a promising novel material with pozzolanic properties which are comparable to that of coal fly ashes. Then, coal bottom ash subjected to an adequate mechanical grinding is suitable to be used to produce common coal-ash cements.


2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
Qu Jili ◽  
Wang Junfeng ◽  
Batugin Andrian ◽  
Zhu Hao

Abstract Fine aggregates of construction waste and fly ash were selected as additives to modify the characteristics of Shanghai clayey soil as a composite. The laboratory tests on consistency index, maximum dry density, and unconfined compressive strength were carried out mainly for the purpose of comparing the modifying effect on the composite from fine aggregates of construction waste with that from fly ash. It is mainly concluded from test results that the liquid and plastic limit of the composites increase with the content of two additives. But their maximum dry density all decreases with the additive content. However, fine aggregates of construction waste can increase the optimum water content of the composites, while fly ash on the contrary. Finally, although the two additive all can increase the unconfined compressive strength of composites, fly ash has better effect. The current conclusions are also compared with previous studies, which indicates that the current research results are not completely the same as those from other researchers.


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