Calcined Shale and Palm Oil Fuel Ash as Partial Replacements for Calcium-Based Binders to Enhance Compaction Properties of Marine Clay

ABSTRACT

Marine clay is a problematic soil; therefore, its properties have been improved by mixing calcium-based binders, with reinforcing components. However, these materials exhibit many shortcomings, and better options are sought. Calcined shale (CS) is frequently used in concrete as a supplementary cementitious material, but it has not yet been used in soil stabilization. This study investigates the partial replacement of lime in marine clay treatment with CS and palm oil fuel ash (POFA). This study comprises two parts. In Part (1), POFA – lime-treated marine clay was assessed to determine the optimum proportion of POFA. In Part (2), CS – POFA – lime-treated marine clay was evaluated to determine the optimum ternary blending mixtures through many tests. Results of Part (1) indicate that the optimum proportion of POFA is 5%. In Part (2), CS exhibits effective enhancement in the properties of marine clay, and the optimum mixture was 10% CS, 5% POFA, and 3% lime. When lime content was reduced from 5% to 1% through replacement with CS, maximum dry density and optimum water content increased by 1.7% and 5.2%, respectively. Hence, CS can be effectively used as a partial replacement for lime in marine clay treatment.

摘要

海洋粘土的使用可能存在问题，因此，通过将水泥和石灰等钙基粘合剂与增强成分混合，其性能得到了改善. 然而，这些材料显示出许多缺点，并寻求更好的选择. 煅烧页岩（CS）是混凝土中常用的一种辅助胶凝材料，但尚未用于土壤稳定. 本研究研究了用CS和棕榈油燃料灰（POFA）部分替代海洋粘土处理中的钙基粘合剂. 本研究包括两个部分. 在第（1）部分中，对POFA-石灰处理的海洋粘土进行了评估，以确定POFA的最佳比例. 在第（2）部分中，对CS– POFA–石灰处理的海洋粘土进行了评估，以通过阿太堡极限、压实度、比重和固结测试来确定最佳的三元混合混合物. 第（1）部分的结果表明，POFA的最佳比例为5%. 在第（2）部分中，CS对海洋粘土的性能表现出有效的增强作用，最佳混合物为10%CS、5%POFA和3%石灰. 当用CS替代石灰时，石灰含量从5%降低到1%，最大干密度和最佳含水量分别增加1.7%和5.2%. 因此，可以得出CS在海洋粘土处理中作为石灰的部分替代物是有用的结论.

KEYWORDS:

• Marine clay
• lime
• palm oil fuel ash (POFA)
• Calcined shale (CS)
• compressibility behavior
• compaction

关键词:

• 海相粘土
• 石灰;棕榈油煤灰(POFA)
• 煅烧页岩(CS)
• 压缩性能
• 压实

Highlights

• Marine clay has many problems, such as high compressibility and low shear strength.

• Calcined shale (CS) material has not been used for soil stabilization yet. 

• Calcined shale (CS) decreases the production of CO2 emissions and sulfate attacks from the other supplementary cementitious materials (cement and lime) that cause environmental and structural issues. 

• Calcined shale (CS) enhance the strength and compressibility behavior  of lime-treated marine clay.

• Calcined shale (CS)  has the potential to be used as a partial replacement of lime in marine clay treatment.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

This study does not involve any human or animal subjects.

Additional information

Funding

This research received no specific grant from any funding.