The present experimental study evaluates the overburden correction factor (K6) of different pond ash samples under earthquake loading for liquefaction analysis. A series of 54 stress-controlled cyclic simple shear tests was conducted on pond ash specimens at different overburden pressures and cyclic stress ratios. Cyclic resistance ratio (CRR) was evaluated for each pond ash sample at different overburden pressures using two criteria based on maximum excess pore water pressure and double amplitude shear strain to evaluate the K6. The K6 values obtained for the pond ash were compared with the K6 values for natural soils (clean sand and sand-silt mixtures). The cyclic resistance ratio (CRR) and K6 values were observed to decrease with an increase in overburden pressure from 50 kPa to 100 kPa, and a further increase in overburden pressure to 150 kPa led to an increase in CRR and K6 values for pond ash specimens with fine particles dominated matrix. However, an opposite trend was observed for pond ash specimens with coarse particles-dominated matrix. The unique response of K6 values for pond ash was found to be significantly different from the already available K6 response for natural cohesionless soil (clean sand and sand-silt mixtures) as it unavoidably included the effect of OCR and void ratio along with the vertical overburden pressure.

This study evaluated the strength and durability characteristics of pond ash (PA) treated with geopolymer (3%, 6%, 9%, 12%, and 15%, by dry weight of PA) and compared them with Portland cement and hydrated lime stabilizations at same additive contents. Unconfined compressive strength of specimens was evaluated at curing durations of 1, 3, 7, 28, and 90 days. The durability of 28-day cured stabilised specimens against wet-dry cycles, freeze-thaw cycles, water slaking cycles, water immersion, capillary action, and dispersion was assessed. Geopolymer-stabilized PA achieved higher strength and durability than cement and lime-stabilised PA. It is due to the formation of a dense microstructure with significant reaction products. PA stabilised with 3% geopolymer and 15% cement satisfies the strength properties of the cementitious subbase in flexible pavements. Whereas, 6% geopolymer content fulfils the requirements of the cementitious base in flexible pavements and the cementitious subbase in rigid pavements as per IRC: 37-2018 and IRC: 59-2015, respectively.

The nominal buffer layer combination is evaluated in this paper to control swell and improve the strength property of expansive soils by using geomembrane (G) and various buffer layer materials such as river sand (RS), pond ash (PA) and murram (M). Different combinations of buffer layer, percentage of stabilizing agents (lime, L, and cement, C), and conditions (cured (C) and uncured (UC)) were used to conduct tests. The expansion ratio (ER) was found to be not significantly reduced in combinations with untreated buffer layers when compared to treated buffer layers. ER was further reduced in combinations with geomembrane, demonstrating that geomembrane prevented water movement and prevented Black Cotton (BC) soil from becoming saturated. Three criteria were used to assess the optimal combination: reduction in swell, gain in strength, and feasibility. BC + G + BC3%L + RS (C) and BC + G + M6%L + PA (C) both fit the requirements for construction on expansive soils.

Clays often have unfavorable geotechnical properties that limit construction applications on them. There is a need for sustainable soil improvement techniques to enhance the strength and stiffness of clays. While previous studies have explored clay stabilization with common supplements like cement, lime and fly ash, the utilization of sludge pond ash (SPA) as a sustainable additive has been limited and there is a lack of understanding of the interactive effects of SPA proportion, moisture content, and curing time on the mechanical behavior of clay. The objective of this study is to examine the mechanical properties of clay enhanced with SPA under different curing conditions. To achieve this, different proportions of SPA were mixed with the clay to obtain accurate findings on the efficacy of SPA addition on compaction and unconfined compressive strength (UCS) of the clay to determine mechanical properties. Scanning electron microscopy (SEM) provided imaging of clay improved with SPA to evaluate the microstructural changes in soil texture. Firstly, the sludge from a pond burned at 1000 degrees C (the optimal temperature determined by microstructural X-ray diffraction (XRD) analysis) was added to the mixture as 0, 2, 4, 6, 8 and 10% of the soil's dry weight, respectively. The studied samples were prepared with the same energy (equivalent to the standard Proctor test) at different moisture contents and were tested in a uniaxial device at 7, 28 and 56 days of curing. It was found that adding SPA to the base soil decreased the maximum dry unit weight (MDUW). On the other hand, it increased the optimum moisture content (OMC) of the compacted mixture. The study examined the combined effects of moisture content and curing time on the compounds, revealing that these factors induced a decrease and an increase in the UCS, respectively. The addition of SPA as an additive material to the clay mixture was found to exert a significant effect on the strength properties of the clay, with an optimal percentage of around 10%. Empirical correlations were also developed to predict the UCS of the SPA-improved clay with high precision. Furthermore, SEM analyses show that SPA acts as a glue gel between aggregate in the mixture and coat clay particles that changes the blend texture and alters weak bonding to aggregate-like particles. The results of both macro-and micro-scale analyses collectively confirm the superior efficacy of the optimal SPA replacement in enhancing various strength and stiffness properties of the clay.

Owing to the order of the day, we are searching for an ecofriendly binding ingredient instead of cement, which is now universally used in concrete. Almost everyone extensively exploits construction materials due to their good durability and compressive characteristics. The present study examines the use of Acacia nilotica ash as a cement substitute. It is known that Acacia nilotica`s aggressive roots are extremely presumptuous and invasive and spoil the foundation of buildings. By gripping water from adjoining areas, they change soil nitrogen and are a major source of affecting plant growth. In this work, the M 35- grade geocomposite was investigated by incorporating Acacia nilotica ash at 0%, 2.5, 5%, 7.5%, 10%, 12.5%, and 15% for fly ash. Mechanical and durability studies were carried out by changing the magnitude of Acacia nilotica ash and evaluating it with the standard composite samples.

The subgrade is a crucial part of the pavement structure, as it transmits the load of vehicles on the pavement to the subsoil. The stability of the pavement depends on the stability characteristics of the subgrade. Roadwork waste materials (RWM) constitute a significant portion of waste materials used for roadway construction, particularly in base fill and backfill layers. Due to the shortage of virgin raw aggregates from quarries, alternative materials, such as RWM, are used as replacements in regular roadway construction. This research conducted a wide range of laboratory and field evaluations to determine the engineering properties of pond ash (PA) and reclaimed asphalt pavement (RAP), focusing on bottom ash as a blended material. Geotechnical parameters, such as particle size and mechanical properties of the materials, were assessed to evaluate their performance in pavement base or sub -base applications. The interaction of integrity between pond ash, RAP, and natural backfill as homogeneous materials was assessed by examining consistency characteristics concerning optimum moisture content (OMC) and maximum dry density (MDD). Six proportions of pond ash, RAP, and backfill soil (PA, RAP, NBS) were identified and used, with the optimal proportion being 50%:30%:20%. The grain size of RAP required for soil testing suitability will be obtained by disintegration using an earth hammering machine.