Study of Strong Interlocked Skeleton Dense Gradation for Cement-Stabilized Macadam

2013 ◽  
Vol 438-439 ◽  
pp. 644-648 ◽  
Author(s):  
Zhe Jiang Chen ◽  
Jin Shun Xue ◽  
Fan Cao ◽  
Ying Jun Jiang

In order to improving the performance of Cement-stabilized Macadam (CSM), analyzing the influences of its composition structure on performance, and then putting forward the gradation design principles and strong interlocked framework dense gradation (SISDG), laboratory test was adopted to verify its road performance. Result shows that CSM has the feature of the amount of aggregate above 9.5 mm, below 4.75 mm and 0.075 mm are more, while the amount of aggregate 4.75-9.5 mm is less, and the California Bearing Ratio (CBR) value of mineral aggregate with SISDG is increased by 8~14% comparing with mineral aggregate with the framework dense-graded (DSDG) presented in Design Specifications of Highway Asphalt Pavement (JTG D50-2006) gradation. Compared with CSM with DSDG, 28d unconfined compressive strength (UCS), ultimate UCS and splitting strength of CSM with SISDG are respectively increased by 6~12%, 8~20% and 8~15%.

2014 ◽  
Vol 695 ◽  
pp. 93-97 ◽  
Author(s):  
Aminaton Marto ◽  
Nor Zurairahetty Mohd Yunus ◽  
Faizal Pakir ◽  
Nima Latifi ◽  
Ahmad Hakimi Mat Nor ◽  
...  

The presence of marine clay in Iskandar Malaysia Region, Nusajaya had caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of Biomass Silica (BS), one of the commercial brands namely “SH-85” to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the Atterberg limits and Unconfined Compressive Strength (UCS) for treated and untreated of marine clay soils. The proportions of BS added were 3, 6, 9, 12 and 15% and tested at 0, 3, 7 and 28 days curing periods. The results shows that the Plasticity Index (PI) was reduce with increment of BS content. While, an addition of BS content increase in strength treated soils 60 times more than untreated soils, which is gain in early 7 curing days period. This finding indicates the BS is a suitable stabilizer for the marine clay to become strong foundation for construction of road and building.


Author(s):  
Zhenxia Li ◽  
Tengteng Guo ◽  
Yuan Zhao Chen ◽  
Xu Zhao ◽  
Yanyan Chen ◽  
...  

Abstract In order to solve the environmental pollution of coal gangue and the shortage of aggregate resources in road engineering, waste coal gangue is used as road base material instead of natural stone materials. Through physical, mechanical, chemical and activity tests of coal gangue aggregate, the optimal gradation composition of unconfined compressive strength was determined. Through unconfined compressive strength, indirect tensile strength, flexural tensile strength, freeze-thaw and dry shrinkage tests, the influence of cement content on road performance of cement stabilized coal gangue mixture was studied. By means of SEM, ICP AES, XRD and optical digital microscope, the difference between spontaneous combustion coal gangue and Unspontaneous combustion coal gangue was analyzed, the microstructure of cement stabilized coal gangue mixture was characterized, and the strength formation mechanism of mixture was explored. The results show that Spontaneous combustion coal gangue has higher activity than Unspontaneous combustion coal gangue.Based on the selected optimal allocation(BNS:SNS:SSC =71.26:9.41:18.8),The mixture of 4% cement dosage can not only meet the requirement of early strength 4.16 MPa, but also show an efficient strength growth rate of 36.10%, showing the optimum mechanical properties. The total shrinkage coefficient of cement stabilized coal gangue mixture with 4% cement dosage is 1.12×10-2, which shows that the dry shrinkage resistance is the best. With the increase of time, hydration degree is gradually deepened, and gelled substance is more tightly bonded to aggregates. There is no obvious gap between aggregates, and the integrity of the mixture is enhanced, which can show better road performance. Ca (OH)2, a cement hydration product in cement stabilized coal gangue mixture, takes place pozzolana reaction with active SiO2 and Al2O3 in coal gangue to produce gismondine, which is beneficial to the global strength and the bond quality of the mixture.


2019 ◽  
Vol 8 (2) ◽  
pp. 6252-6257

Clayey soils are considered as the weakest subgrade soil from civil engineering point of view under moist condition. These soils attract and absorb water and loses their strength. Because of this reason certain inherent properties of these clayey soils need modification for their bulk use in construction of highways, embankments etc. Recently, many synthetic fibres have emerged to strengthen soft soils. Synthetic fibres are low-cost materials, hydrophobic and chemically inert in nature which does not allow the absorption or reaction with soil moisture. The inclusion of synthetic fibres provides reinforcement to the soil and use of lime as a soil stabilizer in BC soil cut down the plasticity index and also increase its strength. For this an extensive laboratory test program was conducted to analyse the variation geotechnical properties of soil by changing the percentage of recron fibre at an optimum dose of lime. The laboratory tests include Atterberg Limit Test, Modified Proctor Test, Unconfined Compressive Strength Test and California Bearing Ratio Test. To conduct different tests on soil sample the proportion of lime is kept fixed and proportion of polyester recron fibre is varied from 0% to 1% by dry weight of soil sample for different lengths of fibre(6 mm, 12 mm & 18 mm separately). Optimum dose of lime is find out by plasticity index of BC soil mixed with varying percentages of lime (4%, 6%, 8% and 10%). Results of the experiments shows that with the increase in the appropriate percentage in recron fibre the Unconfined Compressive Strength and California Bearing Ratio increases. On increasing the length of Recron Fibre, the Unconfined Compressive Strength and California Bearing Ratio also increases. Combination of lime and recron fibre in BC soil give higher CBR value. Therefore it can be used in the improvement of Clayey Soil Subgrade in pavement design and in the construction of embankements.


2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Anigilaje B Salahudeen ◽  
Ja’afar A Sadeeq

The study investigate the suitability of subgrade soil in Baure Local Government Area of Kastina State Nigeria for road construction. The strength properties of the  subgrade was improved using lime and cement. Several analysis including the particle size distribution, specific gravity, Atterberg limits, compaction characteristics, unconfined compressive strength and California bearing ratio tests were performed on natural and lime/cement treated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990) respectively. Soil specimens were prepared by mixing the soil with lime and cement in steps of 0, 3, 6, and 9% by weight of dry soil in several percentage combinations. The Atterberg limits of the weak subgrade soils improved having a minimum plasticity index value of 5.70 % at 3%Lime/6%Cement contents. The maximum dry density (MDD) values obtained showed a significant improvement having a peak value of 1.66 kN/m3 at 9%Lime/9%Cement contents. Similarly, a minimum value of 18.50 % was observed for optimum moisture content at 9%Lime/9%Cement contents which is a desirable reduction from a value of 25.00 % for the natural soil. The unconfined compressive test value increased from 167.30 kN/m2 for the natural soil to 446.77 kN/m2 at 9%Lime/9%Cement contents 28 days curing period. Likewise, the soaked California bearing ratio values increased from 2.90 % for the natural soil to 83.90 % at 9%Lime/9%Cement contents. Generally, there were improvements in the engineering properties of the weak subgrade soil when treated with lime and cement. However, the peak UCS value of 446.77 kN/m2 fails to meet the recommended UCS value of 1710 KN/m2 specified by TRRL (1977) as a criterion for adequate stabilization using Ordinary Portland Cement.            Keywords: Weak subgrade soil, Lime, Cement, Atterberg limits, Maximum dry density, Optimum moisture content, Unconfined compressive strength, California bearing ratio


2020 ◽  
Vol 26 (7) ◽  
pp. 145-157
Author(s):  
Zozk Kawa Abdalqadir ◽  
Nihad Bahaaldeen Salih ◽  
Soran Jabbar Hama Salih

The clayey soils have the capability to swell and shrink with the variation in moisture content. Soil stabilization is a well-known technique, which is implemented to improve the geotechnical properties of soils. The massive quantities of waste materials are resulting from modern industry methods create disposal hazards in addition to environmental problems. The steel industry has a waste that can be used with low strength and weak engineering properties soils. This study is carried out to evaluate the effect of steel slag (SS) as a by-product of the geotechnical properties of clayey soil. A series of laboratory tests were conducted on natural and stabilized soils. SS was added by 0, 2.5, 5, 10, 15, and 20% to the soil. The conducted tests are consistency limits, specific gravity, hydrometer analysis, modified Proctor compaction, swelling pressure, swelling percent, unconfined compressive strength, and California Bearing Ratio (Soaked CBR). The results showed that the values of liquid limit, plasticity index, optimum moisture content, swelling pressure, and swelling percent were decreased when stabilized the soil. However, the values of maximum dry density, unconfined compressive strength, and California bearing ratio were increased with the addition of steel slag with various percentages to the clayey soil samples. The steel slag was found to be successfully improving the geotechnical properties of clayey soils.


2019 ◽  
Vol 136 ◽  
pp. 04078
Author(s):  
B. Li

The research on the strength influence of pile driving disturbance on the surrounding soil on marine environment is very less. This article is an actual pile driving project in the sea, the soil samplings with different distance from pile was taken and some laboratory test was done, the influence of soil property when pile driving is founded. According to the experimental results, the shear stress parameter and unconfined compressive strength index of soil in the hole increased with the increase of drilling depth, and the unconfined compressive strength index of soil in the hole nearly returned to the level of undisturbed soil 39 days after piling.


Author(s):  
Ramzi Taha

Road rehabilitation and reconstruction generate large supplies of reclaimed asphalt pavement (RAP) aggregate, and recycling into asphalt paving mixtures is the predominant application. Cement kiln dust (CKD), also known as cement bypass dust, is a by-product material generated during production of portland cement. In Oman, where recycling of pavement materials is not practiced, a first attempt was made at combining two by-product materials for use in road construction. Conservation of natural resources and preservation of the environment are two benefits that could be gained by reusing waste materials. The potential use in road bases of CKD-stabilized RAP and RAP with virgin aggregate mixtures was investigated. Physical, compaction, and unconfined compressive strength tests were conducted on RAP and virgin aggregate blends of 100% to 0%, 90% to 10%, 80% to 20%, and 0% to 100%. Samples were prepared using CKD at 0%, 3%, 5%, 7%, 10%, 15%, and 20% and were cured for 3, 7, and 28 days in plastic bags at room temperature. Results indicate that the maximum dry density and unconfined compressive strength of RAP generally increase with addition of virgin aggregate and CKD. The moisture content-dry density curves for CKD-stabilized RAP aggregate mixtures did not show a distinctive peak similar to that of the 100% virgin aggregate blend. Longer curing periods will produce higher strength values. CKD content of 15% seems to be the optimum for achieving maximum strength.


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