## 1 Introduction  
Vast deposits of marine clay soil are typically linked with poor engineering properties such as low shear strength, high compressibility and low permeability [1; 2; 3; 4]. The marine clay soil is usually found at the coastal area in Peninsular Malaysia especially at Alor Setar, Penang, Klang and Malacca. These types of soil mainly posed a significant challenge and problems in designing, construction of building and infrastructure. Recent development nowadays is concerned with obtaining better performance of stabilization by reducing the usage of cement-based binder with a minimal environmental cost. A variety of stabilization soil techniques have been applied to address the problems where one of the major techniques uses chemical stabilization. Lime is one of the traditional chemical stabilizers that has been extensively used internationally. A stabilizer known as a calcium-based binder is a common technique used to improve the performance of soil due to its robustness, easy adaptability and obvious cost effectiveness [5]. Usage of lime as soil treatment resulted in increasing the concentration of pore water which changed the texture of the soil particles to form aggregates [6]. The benefits of applying the lime in marine clay soil have been widely reported by many of the past researchers [7; 8; 9]. The application of lime in the soil has been reported to have a strong bonding between the soil particles, which, through the reactions, results in a reduction of the compressibility of the soils, swelling, shrinkage, plasticity and makes the soil mixture more resistant [6; 10]. Alkaline activation (AA) has grown as one of the binders that were introduced as a replacement of cement due to the environmentally friendly materials and low emission of carbon dioxide. It is also known as one of the \"geopolymers\", where it is touted for its high performance (in terms of durability and strength), low energy consumption and low CO2 emission [11]. [12; 13] stated that the binders are formed by the reaction of amorphous aluminosilicate source with alkali which is usually either alkali-earth (Ca) metals, potassium(K) or sodium hydroxide (Na) that was included in the dissolution of the mineral aluminosilicates and followed by the condensation and hydrolysis of the silica (Si) and alumina (Al) components which are consequential in the formation of a three dimensional, essentially aluminosilicate gel and are amorphous. Particularly, usage of the waste material as a precursor for AA is due to the element that is rich with silica (Si) and aluminium (Al), which helps in binding gel in soil voids and thus perform a formation of sodium aluminium silicate hydrate (N-A-S-H) or calcium aluminium silicate hydrate (C-A-S-H) [5]. Many past studies [5; 14; 15; 16; 17; 18] have reported on the effectiveness of the AA as the stabilizer which significant in the improvement of the soil strength, helps in compacting the microstructures as well as filling the voids inside the soil. Presently, fibre has also been used as a mixture in the soil to improve the behaviour of the soils. However, the focus nowadays is on environmental and sustainability awareness which is more likely to involve natural fibre that is used as reinforcement in the soil matrix. Many past researches have conducted a test by including different types of fibre such as geo- fibre, jute, nylon, sisal fibre, kenaf fibre, palm fibre and many other types of fibre at different types of soil. They concluded that inclusion of the fibre in the soil increased the ductility, compressive strength, and moisture content, and reduced the maximum dry density of soil, increased tensile strength and enhanced the strength of the California Bearing Capacity (CBR) [17; 19; 20; 21; 22]. Coir fibre is one of the natural fibres that is found to have a good strength characteristic and resistance to biodegradation over a long period of time [23].