scholarly journals An Experimental Study of the Road Performance of Cement Stabilized Coal Gangue

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 993
Author(s):  
Junfeng Guan ◽  
Meng Lu ◽  
Xianhua Yao ◽  
Qing Wang ◽  
Decai Wang ◽  
...  

The research into the road performance of coal gangue is of great significance for the consumption of coal gangue and reducing pollution. In this paper, the coal gangues were prepared by separation and crushing processes, and their gradations were also optimized. Aiming to identify the possible problems of coal gangue as a pavement base, an unconfined compressive strength test, a splitting test, a freeze–thaw test, and a drying shrinkage test of cement stabilized gangue with varying cement amounts were carried out, and the test results were compared and analyzed. The test results showed that the maximum dry density and optimum moisture content (OMC) of the optimized cement stabilized gangue and cement stabilized macadam increased with cement content. The maximum dry density and OMC of cement stabilized macadam were larger than that of cement stabilized gangue with the same cement content. The optimized 7-day unconfined compressive strength of cement stabilized gangue can meet the requirements for a secondary and lower highway base and subbase. The OMC and cement content are the critical factors affecting the compressive strength loss rate of cement stabilized gangue after freeze–thaw cycles. The smaller the OMC of cement stabilized gangue and the larger the cement content, the lower the compressive strength loss rate. With an increase in cement content, the drying shrinkage strain of cement stabilized gangue increased. The results show that a cement content of 4% is optimal for the cement stabilized coal gangue, which can be used for the light traffic base and heavy traffic subbase of class II and below highways. It provides a basis, guide, and reference for the application of coal gangue materials in a high-grade highway base.

2012 ◽  
Vol 626 ◽  
pp. 34-38
Author(s):  
Ary Setyawan ◽  
Anastasia Muda ◽  
Sholihin As’ad

Road rehabilitation and reconstruction generate large supplies of reclaimed asphalt pavement (RAP). One of the efforts to reuse the RAP is by insitu process and utilize it as road base materials. To get satisfying result from the RAP, it is necessary to add a certain amount of Ordinary Portland Cement (OPC) as stabilizer. This study investigate the potential use of OPC-stabilized RAP in road bases. Laboratory experimental method was applied by using material collected from road located at Boyolali-Kartasura as the object of the study with the cement content variations of 4%, 5% and 6% for unconfined compressive strength test (UCS) and the cement contents variation of 5% and 6% for drying shrinkage test. The range of cement contents required for unconfined compressive strength of cement treated recycling base (CTRB) are 5% to 6%. The cement content used at Boyolali - Kartosuro road rehabilitation was 5.5%. Drying shrinkage during 28 days is 805.3 micro strain for the cement content of 5% and 826.3 micro strain for the cement content of 6%. The drying shrinkage of the materials was quite high for CTRB, so that carefully design and attention need to take into account to avoid the cracks at the road base and the prospective of reflective cracking at the surface course of the road.


2021 ◽  
Vol 1197 (1) ◽  
pp. 012077
Author(s):  
K.S Chamberlin ◽  
M. Rama Rao

Abstract Expansive soils are found in black cotton soils, which swell or shrink in volume when presented to changes in moisture content. Lime treatment is exhaustively used to increment the properties of sensitive and fragile soils. One of the hugest clarifications behind using lime is to decline the developing presentation of the earth soil. The arrangement of extra safeguards improves the reaction of quicklime (CaO) with water, structures hydrated (slaked) lime (Ca (OH)2), and thus earth characteristics. The vast inadequacy of employing lime is growing the deficiency of lime offset earth. Following that, the goal of this study is to see how re-establishing time affects the geotechnical qualities of settled Black cotton soils with lime. These discoveries recommend that adding Lime as a stabilizer works on the strength of black cotton soil. Some of the characteristics of the soil likely to be increased by using stabilizer in this work are UCS (Unconfined Compressive Strength) at different curing periods (7,14,28 and 56 days), CBR (California Bearing Ratio) value at unsoaked and soaked and MDD (Maximum Dry Density) decrease at different lime percentages(%) like 2.4.6.8 and 10. The result showed here untreated soil got stabilized by using the stabilizer in certain extent In this adjustment various rates of cementitious material is added to black cotton soil and directed tests like plasticity, compaction, swell pressure, free swell index(FSI), Coefficient of permeability (k) and CBR(soaked and unsoaked) at various conditions like OMC,OMC+2% water and OMC+5% water, UCS (Unconfined Compressive Strength) was performed. From the test results, it is identified that the stabilization agent decreases plasticity and improves strength characteristics. Addition of stabilizing agent makes the black cotton soil to non-plastic, non-swelling and attains increase CBR values which are greater than 25% for a dosage of 10% lime at OMC but remaining OMC+2%water & OMC+5%water CBR values are not various much difference as per test results. With the addition of lime, the black cotton soil becomes non-plastic, non-swelling, and has high strengths. Treated soils are used as a development material, for example, a subgrade layer in the development of adaptable asphalt pavements for roads.


2014 ◽  
Vol 61 (1) ◽  
pp. 43-58 ◽  
Author(s):  
Alaa M. Rashad ◽  
Hosam.El Din H. Seleem

Abstract This paper presents the results of an investigation to assess the validity of producing high strength concrete (HSC) using moderate cement content to reduce the consumption of the binders. Cement content is lowered from 500 kg/m3 to 400 kg/m3. The difference in cement content is compensated by the addition of fine limestone (LS) powder. Pozzolans were incorporated as an addition to cement. Different coarse aggregate types were employed. Workability, compressive strength, tensile strength, permeability and drying shrinkage were measured. Test results revealed that HSC with a compressive strength up to 79 MPa (at 90 days age) could be produced with moderate cement content. The mixtures consistency and drying shrinkage are greatly enhanced due to employing LS powder and the permeability is satisfactory. To provide better solution to some concrete disadvantages like cracking and drying shrinkage, using an economic rate for cement are believed to reduce these disadvantages.


2021 ◽  
Vol 3 (1) ◽  
pp. 22-32
Author(s):  
Anthony Mugendi Nyagah ◽  
Sixtus Kinyua Mwea ◽  
Francis John Gichaga

Among the developing nations, unpaved (gravel and earth) roads form a disproportionately large percentage of the road network when compared to the paved roads. For instance, in Kenya earth roads account for 47% of the road network, while the gravel roads account for about 38%. The most significant problem associated with gravel and earth roads is dust emission, which contributes to the deterioration of the road surface. In addition, the dust causes road safety, human health and the environmental quality issues. In order to minimize dust emission dust suppressants are applied annually. Dust suppressants, for example, Magnesium or Calcium Chlorides solutions are expensive and hence not widely used in developing countries like Kenya. In many Kenyan rural homes and in most African countries, fresh cow dung (FCD) is used as dust suppressants in madhouses. Therefore, this study seeks to explore the mechanical and binding potentials of FCD for gravel roads construction as a dust suppressant, improvement of mechanical and resilience properties of lateritic soils for gravel roads construction. The effect of FCD on gravel soils was determined at various percentages (0%, 3%, 6%, 9% and 12%) by weight. The Index properties, compaction properties, plasticity requirements and bearing strengths {Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR)} were determined. The results show that Maximum Dry Density (MDD) reduced while the Optimum Moisture Content (OMC) increased with the increase in dosages of FCD. The UCS test results were 257 kN/m2 (0%), 257 kN/m2 (3%), 300 kN/m2 (6%), 267 kN/m2 (9%) and 213 kN/m2 (12%) while, the CBR test results were 21%, 39%, 54%, 34%, and 24% for 0%, 3%, 6%, 9% and 12%. The research concludes that FCD at 6% by weight can be used for mechanical stabilization of gravel soils for road construction. FCD is cheaper, readily available, sustainable and environmentally friendly. This will go a long way in the economic development of low and middle-income countries.


2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Olumide M Ogundipe ◽  
Jonathan S Adekanmi

Two different samples of soil tested as A-7-5 and A-7-6 were stabilized respectively with lime and cement. The samples were stabilized with the additives in steps of 2% and subjected to laboratory tests such as consistency limits, compaction, California bearing ratio (CBR) and unconfined compressive strength (UCS) until it reached 10% additives by weight of dry soil sample. The Proctor energy type of compaction and soaked method of CBR was adopted for the research while the compressive strength of the soils were measured in an unconfined state at days 1, 7 and 14 respectively. The plasticity index (PI) of the soil samples increase at 2% additives which later reduces with further increase as the additives contents. The soil samples attained their maximum dry densities at 6% cement and lime respectively, with cement being more effective compared to lime and the water content needed to achieve maximum dry density of the soil were higher in cement than in lime. The CBR values of the soil appreciate with increase in the additives content as indicated in the rise from 1.12% at natural to 7.26% at 6% cement content. The UCS of the lime stabilized soil improved better than that of cement stabilized soil with respect to the age of curing.  Keywords- Stabilization, Lime, Cement, Soil, Laterite.


2019 ◽  
Vol 972 ◽  
pp. 50-56
Author(s):  
Akanksha Bhurtel ◽  
Amin Eisazadeh

Expansive clayey soils like Bangkok clay can shrink and swell with water contact. Therefore, the presence of such soils tends to damage the road conditions with a higher frequency of rainfall in Thailand. The presence of expansive clayey soil has brought the concept of stabilization of such roads with any other stronger materials. This paper shows the test results on the moisture-density relationship of bottom ash and lime stabilized Clayey soil to use as a pavement material in Thailand. In this study, a waste material produced from coal combustion called bottom ash was used as a replacement material and quicklime as a binding material. During the tests 10%, 20%, 30% and 50% bottom ash and 4%, 8%,12% Lime were used. The result shows a decrease in Maximum Dry Density and increase in Optimum Moisture Content with an increase in each amount of replacement material.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ubido Oyem Emmanuel ◽  
Igwe Ogbonnaya ◽  
Ukah Bernadette Uche

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.


2021 ◽  
Vol 11 (3) ◽  
pp. 1037
Author(s):  
Se-Jin Choi ◽  
Ji-Hwan Kim ◽  
Sung-Ho Bae ◽  
Tae-Gue Oh

In recent years, efforts to reduce greenhouse gas emissions have continued worldwide. In the construction industry, a large amount of CO2 is generated during the production of Portland cement, and various studies are being conducted to reduce the amount of cement and enable the use of cement substitutes. Ferronickel slag is a by-product generated by melting materials such as nickel ore and bituminous coal, which are used as raw materials to produce ferronickel at high temperatures. In this study, we investigated the fluidity, microhydration heat, compressive strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including ferronickel-slag powder and fly ash. According to the test results, the microhydration heat of the FA20FN00 sample was slightly higher than that of the FA00FN20 sample. The 28-day compressive strength of the FA20FN00 mix was approximately 39.6 MPa, which was higher than that of the other samples, whereas the compressive strength of the FA05FN15 mix including 15% of ferronickel-slag powder was approximately 11.6% lower than that of the FA20FN00 mix. The drying shrinkage of the FA20FN00 sample without ferronickel-slag powder was the highest after 56 days, whereas the FA00FN20 sample without fly ash showed the lowest shrinkage compared to the other mixes.


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.


2010 ◽  
Vol 152-153 ◽  
pp. 1176-1179 ◽  
Author(s):  
Feng Lan Li ◽  
Qian Zhu

To improve the application of the new proto-machine-made sand in structural engineering, tests are carried out to study the drying shrinkage of concrete affected by stone powder in proto- machine-made sand. The target cubic compressive strength of concrete is 55 MPa, the main factor varied in mix proportion of concrete is the contents of stone powder by mass of proto-machine-made sand from 3 % to 16 %. The drying shrinkage strains of concrete are measured by the standard method at the ages of 1 d, 3 d, 7 d, 14 d, 28 d, 60 d, 90 d, 120 d, 150 d and 180 d. Based on test results, the drying shrinkage of concrete affected by the contents of stone powder in proto-machine-made sand is analyzed and compared with that of similar test of concrete with traditional machine-made sand, which shows that there is the optimum content of stone powder resulting in the lower drying shrinkage of concrete. The formula for predicting drying shrinkage strain of concrete is proposed.


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