Browsing by Author "Herath, HMSM"

Now showing 1 - 4 of 4

item: Conference-Abstract
Engineering properties of cement and lime stabilized silty sand in pavement sub bases
Mampearachchi, WK; Herath, HMSM
Chemical stabilization of soils is a widely used practice for improving engineering properties of soil. This technology is used very effectively in developed countries with standard and appropriate machinery specific to them. This study is focused on sensitivity analysis of important parameters of soil stabilization and the effect of nonstandard machinery on improving of medium plastic silty sand soil which is abundantly available in Sri Lanka. Three soil samples of silty sand with medium plasticity which do not meet the specified requirements for subbases were studied. Laboratory test results indicate that both stabilizers improve spil properties up to a considerable degree. Comparison of Unconfined compressive strength (UCS), degree of p^0m verization (DOP) and mixing time for drum mixing and rotary mixing were made and it was found that the rotary mixing provides higher UCS and DOP with a minimum number of mixing cycles. It was observed that the DOP and UCS reduce with extended mixing time in drum mixing and values slightly increase after achieving the maximum in rotary mixer. Two possible compaction scenarios (under prevailing moisture content and ojry timum moisture content relevant to the compaction time) were evaluated for both cement and lime stabilization. Furthermore, variation of the optimum moisture content (OMC) with the time was studied for cement stabilized and lime stabilized soil. Test results show that compaction time (delayed compaction), moisture content at the mixing time and moisture content at the compaction time are crucial factors that must be considered in soil stabilization with cement and lime.
item: Conference-Abstract
Evaluating suitability of soil stabilization methods for local road construction industry
(Department of Civil Engineering, University of Moratuwa., 2010) Herath, HMSM; Mampearachchi, WK; Pasindu, HR
Soil stabilization is defined as any treatment applied to improve its strength and reduce its vulnerability to water. With the rapid development of local infrastructure industry, there is a scarcity of good quality soils which causes to delay of projects, increase of cost as well as decrease the quality of the final product. Therefore it is essential to find out reason for non popularity of soil stabilization and develop some guidelines to effectively used in road construction sites. A survey was conducted among professional in road industry Survey result reviled that only 35% of the participants had a fair knowledge and experience on soil stabilization but 72% and 56 % of participants were skeptical on quality control and the cost respectively. Engineering properties of soil Sample collected from different places were determined and same soil has being used to determine the properties after stabilizing according to the available guideline, with locally available stabilizers ( Cement and Lime).Laboratory test results indicates that both stabilizer improve soil properties in considerable amount and Degree of Pulverization (DOP), mixing time are important parameters in soil stabilizing .Further, field tests are conducted to measure the applicability of stabilization technology using locally available materials and machineries According to the laboratory test results shows 80% degree of pulverization (DOP) is required to gain a higher compressive strength of cement and lime stabilized soil. The effect of delayed compaction showed a strength reduction of 22% for cement and 12% for lime at the OMC. Lime and cement stabilizers increase OMC and therefore compaction should be carried at higher moisture content. .Breaking action is more effective rather than rolling action in soil - stabilizing. So, rotaries may be more effective than motor grader or backhoe (which are presently use)
item: Conference-Extended-Abstract
Evaluating suitability of soil stabilization methods for local road construction industry
(2009) Herath, HMSM; Kumara, MAW
Soil stabilization is not using in local roads construction industry in major scale. Various reasons effects to non popularity and initial part this paper presents the result of questionnaire survey among the professionals who practice in road construction industry. Soil Sample collected from different places, used to determine the engineering 'properties (Sieve Analysis, Liquid Limit (LL), Plastic Limit (PL), California Bearing Ration (CBR) and Unconfined Compressive Strength (UCS)). Same soil has being used to determine the properties after stabilizing according to the mailable guideline, with locally available stabilizers ( Cement and Lime). Laboratory test results indicates that both Stabilizer improve soil properties in considerable amount. Suitable stabilized criteria and quality controlling measures is to be established.
item: Thesis-Full-text
Evaluating suitable soil stabilization method for local road construction industry
Herath, HMSM; Mampearachchi, WK
There has been a rapid development in infrastructures in Sri Lanka since early 90s. Roads and related constructions are the major components of infrastructure development. Due to this construction boom, there is a heavy demand to the construction materials. Availability of natural resources is not sufficient to satisfy demand of the industry. Due to this reason there is a scarcity of good quality natural recourses like soil, metal etc. As a result of this scarcity, many road projects have been delayed in completion and costly. Soil can be identified as one of the major construction material in road constructions. To overcome the dearth of suitable soil for construction, soil modification should be done in major scale. Soil stabilization is a well known soil modification method, commonly used in developed countries. But, soil stabilization is not popular technique in Sri Lanka. The aim of this research is to evaluate the suitable soil stabilization methods for local road construction industry. To determine the real reasons for invisibility of this technology in Sri Lanka, questionnaire survey was done among the professional in the industry. Further, selected sandy clay soil with unsatisfactory engineering properties were used for the investigations. Extensive lab and field tests were conducted to examine the effect of mixing, mixing time and stabilizer type, delay compaction to evaluate the performance of stabilized soil. When consider the availability and suitability of the stabilizers, Cement and Lime are the most appropriate stabilizers for local conditions. Strength variation of cement and lime stabilized soil with the mixing time and degree of pulverization were determined. It was found that, degree of pulverization is a critical factor should be considered in the stabilization. Further, blending action is more effective than rolling action in soil mixing with stabilizers. Influence of compaction delay was another important factor in soil stabilization. It was found in this study that the soil-stabilizer mixing should be done in dry condition and compaction should be done at the relevant optimum moisture content of the mixture at the time of compaction, for the maximum compressive strength. Finally, cost evaluation was carried out to compare the transport sub base material and soil stabilization. As the results of cost comparison, soil stabilization is most suitable for the soil which have properties just out from the specification. There has been a rapid development in infrastructures in Sri Lanka since early 90s. Roads and related constructions are the major components of infrastructure development. Due to this construction boom, there is a heavy demand to the construction materials. Availability of natural resources is not sufficient to satisfy demand of the industry. Due to this reason there is a scarcity of good quality natural recourses like soil, metal etc. As a result of this scarcity, many road projects have been delayed in completion and costly. Soil can be identified as one of the major construction material in road constructions. To overcome the dearth of suitable soil for construction, soil modification should be done in major scale. Soil stabilization is a well known soil modification method, commonly used in developed countries. But, soil stabilization is not popular technique in Sri Lanka. The aim of this research is to evaluate the suitable soil stabilization methods for local road construction industry. To determine the real reasons for invisibility of this technology in Sri Lanka, questionnaire survey was done among the professional in the industry. Further, selected sandy clay soil with unsatisfactory engineering properties were used for the investigations. Extensive lab and field tests were conducted to examine the effect of mixing, mixing time and stabilizer type, delay compaction to evaluate the performance of stabilized soil. When consider the availability and suitability of the stabilizers, Cement and Lime are the most appropriate stabilizers for local conditions. Strength variation of cement and lime stabilized soil with the mixing time and degree of pulverization were determined. It was found that, degree of pulverization is a critical factor should be considered in the stabilization. Further, blending action is more effective than rolling action in soil mixing with stabilizers. Influence of compaction delay was another important factor in soil stabilization. It was found in this study that the soil-stabilizer mixing should be done in dry condition and compaction should be done at the relevant optimum moisture content of the mixture at the time of compaction, for the maximum compressive strength. Finally, cost evaluation was carried out to compare the transport sub base material and soil stabilization. As the results of cost comparison, soil stabilization is most suitable for the soil which have properties just out from the specification.