please follow the instruction :you need to do the things are not highlighted only, please make sure to use australian english, good quality writing is needed and there will be a turnitin. one more thing referencing is need to be around 10-15 more.
things need to do is :
·Feasibility/proof of concept
oInnovation/creativity/originality
·Preliminary findings
oWell-supported recommendations
oCritical analysis
·Project management andtimeline
·Conclusions
·References
·Appendix
Subject: Sustainable road pavements on expansive subgrades Assignemt3: A typical progress report would be around 20 – 30 pages (not including cover page, references or appendices). Please sure there will be a "Turnitin" in this assignment so Plagiarism is not acceptable. · Cover page - project title, student(s), supervisor · Executive summary · Statement of problem · List of design/research questions · Background and literature review · Gap analysis · Methodology and engineering design Those highlighted with yellow are already done in Part one you need to do these under: · Feasibility/proof of concept · Innovation/creativity/originality · Preliminary findings · Well-supported recommendations · Critical analysis · Project management and timeline · Conclusions · References · Appendix s3222911_JieLi_AssessmentTask1 Sustainable road pavements on expansive subgrades 2 Table of Contents Summary .................................................................................................................................... 3 Statement of problem .................................................................................................................. 3 Background and literature review ................................................................................................ 3 Properties of expansive soil ..................................................................................................... 3 Engineering test methods used currently for determining pavement design.............................. 5 Subgrade Treatment methods .................................................................................................. 5 Rehabilitation Methods for Deformed Pavements.................................................................... 6 List of design/research questions ................................................................................................. 6 Methodology............................................................................................................................... 7 Ethical considerations ................................................................................................................. 9 Risk assessment ........................................................................................................................ 10 References ................................................................................................................................ 11 Sustainable road pavements on expansive subgrades 3 Summary Significant engineering challenges have been posed by expansive soils. The cost for repairing already constructed structures over the use of expansive soils is estimated to be several billion dollars annually. Severe damages are done to the overlying structures due to the volumetric change in the expansive soils. The subgrade of any building plays the most important role when it comes to supporting the traffic and bearing of load. Therefore, the construction of pavement over the expansive soils should be employed only after having a suitable working platform for enabling the machinery to operate properly. Various studies have shown that the use of high bearing capacity subgrades is not coherent with the CH soils. In order to provide maximum pavement thickness there is a need to provide lowest CBR readings. This report focuses on the properties of soil expansive and the factors that control these properties so as to decrease the cost of the pavements working towards sustainability. The report presents efficient designs for the expansive soil subgrades. The review of the literature reveals that the usage of lime and fly ash on the soil could be a remedial approach. The validity of this claim will be tested during the laboratory experiments. Statement of problem Due to fluctuation in the moisture content, various volumetric changes appear in the expansive soils which cause cracks in the pavements and other lightly loaded structures. Expansive soil deposits cause heaving which leads to significant cracks of flexible and rigid pavements that are built over expansive soil layers. Mitigation of this problem can be done by preventing access of moisture to the expansive soil deposits. According to a study by Jayatilaka and Lytton (1997), the variation of moisture content in expansive subgrade and restraining of pavement roughness can be reduced by using vertical moisture barriers with impermeable geomembranes. Moisture barriers prevent excessive drying of the subgrade soil during dry seasons and access of water during the wet seasons. Therefore, it helps in reducing the chances of longitudinal shrinkage cracking. However, this approach is costly as it involves complex construction models. One of the most economic and useful method is the stabilisation of chemicals used in expansive soils by using Calcium-based stabilisers like cement and lime. However, this method is not applicable for the soils with high content of sulphate as they form high-swelling substances like Thaumasite and Ettringite. Thus, this study focusses on identifying effective mechanisms that contribute towards the recurring damage to the pavements in order to develop efficient sustainable designs for expansive soil subgrades through adequate remedial approaches. Background and literature review In order to develop sustainable road pavements on expansive subgrades, it is imperative to review the contemporary views on: the properties of expansive soils, current practices and the material test procedures being used for determining the clay properties, current treatment methods of the subgrades