Slake Durability Index Research Articles

Performance of some civil engineering structures on Odukpani clay shale, Southeastern Nigeria

The performance of pavement and bridges on a stretch of 21.4 km of Calabar—Itu highway is the focus of this study. Within this 21.4 km section, the pavement structure has completely failed while the three bridges within this section are still in good structural health as there is no failure of both superstructure and foundation. Three groups of shale soils characterize this stretch; these are Ekenkpon Nkporo, and New Netim Marl. The materials were characterized by both geotechnical and geophysical methods at shallow and deep surface. The Ekenkpon and Nkporo classifies as organic silt and clay with high plasticity (OH) and Inorganic silt, (MH) respectively, while New Netim marl classify as lean clay (CL). Geotechnical shear strength properties determined by Direct shear tests for Ekenkpon indicate cohesion value’C, of 36.1 kN/m2, angle of shearing resistance of 36.8°, that of Nkporo shale with cohesion value as 36 kN/m2 and angle of internal friction as 3.6°. Based on the shear strength properties, Ekenkpon shale has a bearing capacity of 3902.95 kN/m2, Nkporo shale has a value of 667.02 kN/m2, and New Netim Marl with a value of 319.75 kN/m2. Within the load range of 50 kN/m2 to 500 kN/m2 the compressibility values for Nkporo are between 0.29 and 0.23 per MPa, while that of Ekenkpon shale for the same load range is between 0.78 and 1.50 per MPa, showing Ekenkpon shale is highly compressible than the Nkporo shale. Shallow seismic refraction survey involving both p and s-waves were also deployed to evaluate the quality of soils at some locations along this alignment. Results indicate the near the surface horizon which serves as the foundation for highway pavement is composed of soil materials that are highly permeable, dispersive, collapsible, easily eroded as indicated by low Slake Durability Index with values between 6.9 and 51.42%; properties which are all dependent on changes in water content. Whereas at depth, the same soil sequence but stable as permeability to water is very low, hence the stability of bridge foundations in them.

Correlation Between Strength and Durability of Sandstones from the Dumri Formation, Tinau Khola Area, West-Central Nepal

Strength and Durability indices are two significant geotechnical criteria that can describe rock fragments' strength and weathering resistance. The Dumri Formation is the youngest and thickest of the Tansen Group, Lesser Himalaya. A thick succession of medium-grained, bluish-grey quartzose sandstone and red-purple shale represents it. To assess the quality of the sandstones, different laboratory tests and analyses were made to characterize the physical and mechanical properties of the sandstones. Physical properties were greatly influenced by composition and texture. The intact rock strength was figured out by the point load strength index (PLSI) and Aggregate impact value (AIV). Rock durability against slaking was determined using the slake durability index (SDI) test. The strength and durability indices were correlated through regression analysis. Sandstones assessed were classified as lithic and feldspathic wacke. Sandstones exhibited high resistance to slaking and are extremely durable (SDI = 99.53-99.86%) under a two-cycle test. Sandstones are strong to very strong (PLSI = 5.28-8.92 MPa) and possess high impact resistance (AIV = 6-9%). The correlation between PLSI and SDI was found to be high (r=0.86). Similarly, a correlation between AIV and SDI was (r=0.98), and between AIV and PLSI was (r=0.86).

Enhancing weathered slope stability assessment through the integration of slake durability index, elastic modulus of knocking ball, and electrical resistivity tomography.

This research assesses the stability of sedimentary rock slopes in Teloi, Sik, Kedah, by focusing on the mechanical properties of the rock layers and their susceptibility to weathering. Key tests include the slake durability index (SDI), elastic modulus of knocking ball (Ekb), and electrical resistivity tomography (ERT). The incorporation of electrical resistivity tomography (ERT) data through the virtual reality platform facilitates the visualization of subsurface conditions. The variability of strength characteristic of interbedded sedimentary rocks leads to the differential weathering of rock layers, which causes deterioration on the slope structure. The testing revealed significant variability in rock strength, with sandstone displaying higher durability (Id > 17.1%) and elasticity (Ekb: 0.97 to 29.31 GPa) compared to shale and siltstone, which exhibited lower durability and elasticity (Id < 2.2%, Ekb: 0.2 to 2.2 GPa). Utilizing the Wenner array setup, three distinct electrical resistivity lines were established to evaluate subsurface anomalies. The ERT profiles revealed variations in electrical resistivity among different rock types, identifying areas of weaker material, which are siltstone and shale, while high resistivity areas indicate sandstone. Kinematic analysis through the stereonet process revealed direct toppling as the primary failure mechanism, driven by the critical orientations of joint sets J1, J2, and J3. This aligns with on-site observations of hanging sandstone blocks prone to toppling failure. The findings of this research show that the slake durability index (SDI) and the elastic modulus of the knocking ball (Ekb) enhance the assessment of mechanical properties and weathering resistance of interbedded sedimentary rocks. The virtual reality platform was particularly helpful in analyzing and visualizing the sub-surface conditions and enhancing the evaluation of complex geological data. As a conclusion, this integrated method was helpful in the comprehensive geotechnical evaluation of the slopes, enabling the selection of effective stabilization measures by assessing the differential weathering of interbedded sedimentary rock and identifying potential failure zones.

ENVIRONMENTAL ASPECTS OF WASTE-DERIVED BOTTOM BLEND CLAY LINERS INCORPORATING ZEOLITE AND BENTONITE

This research investigated the effects of incorporating bentonite and zeolite into bottom blended clay liners (BBCLs) on their engineering properties and adsorption capacity. BBCLs composed of clay, water treatment residue, and calcium carbide in a 40:40:20 ratio by volume were investigated with the addition of 1, 2, and 3 wt.% bentonite or zeolite. The experimental results indicated that bentonite and zeolite had positive effects on the slake durability index and the equilibrium time for the adsorption of lead (Pb) and chromium (Cr) from the leachate, whereas the unconfined compressive strength (UCS) and coefficient of permeability were negatively affected compared to those of the samples without bentonite and zeolite. At 56 days, the UCS of BBCLs with bentonite and zeolite decreased from 3.4 to 2.2MPa, while the coefficient of permeability of all the samples met the regulatory limit of sanitary landfills, which was given at 1×10-7cm/s. The slake durability index of all samples was lower 50% but it remained higher compared to BBCLs without bentonite and zeolite (approximately doubled). Both additives enhanced the equilibrium time and percentage of Pb and Cr adsorption by about 20% and 200%, respectively. SEM-EDS results show the adsorption of Pb and Cr onto the raw materials, calcium silicate hydrate (CSH), zeolite, and bentonite. Therefore, the addition of zeolite can increase the ability to adsorb heavy metals form leachate, which is suitable for use in secured landfills.

A NOVEL WAY TO CLASSIFY THE SLAKE DURABILITY INDEX OF ROCKS

Slaking, the disintegration of rocks upon exposure to moisture and air, poses significant challenges in engineering applications, such as in slope stability and embankment design. This study improves the slake durability index test by introducing several enhancements to better reflect the field conditions of rocks. A new test methodology is developed which includes a revised slake durability classification table, a novel Discard Method for calculating weight retention in the test drum, and an updated classification chart. The improved methodology considers parameters such as porosity and strength, evaluated through index, Schmidt hammer rebound and point load tests. The new classification table categorizes rocks into durability classes according to the field observations and laboratory test results. The Discard Method improves accuracy by eliminating broken pieces from the durability calculation, addressing the limitations in the suggested method. A Configured Discard Method equation further defines the durability estimation by combining porosity, strength and slake durability data. Field investigations and laboratory tests conducted with various rock types demonstrate that the new classification system provides more accurate and practical assessments of rock durability. This study highlights the importance of effective porosity and strength impact which enhance the reliability of slake durability evaluations, offering a revised classification framework that simplifies field assessments while maintaining the accuracy. Future research should focus on developing these methods and expanding their applicability to diverse geological contexts by including more material to test.

Point Load Strength Index and Slake Durability Index of Marbles from the Kanti Highway, Central Nepal LesserHimalaya

Point Load Strength Index (PLSI) is determined to obtain the strength of the rock, while Slake Durability Index (SDI) offers quantitative data on the mechanical behavior of rocks exposed to cyclic wetting and drying. This study aims to find out such index properties of marbles from the Markhu Formation of Central Nepal, Lesser Himalaya. The study of the strength and durability of marbles is crucial to classifying strength and identifying resistance to weathering, deterioration patterns, and rock quality. Fresh rock samples were collected from 20 different locations within the Markhu Formation, exposed across the Kanti Highway. The SDI and PLSI tests were carried out. The study reveals that the PLSI ranges from 2.54 to 9.08 MPa, and the test samples belong to strong to very strong rock categories according to the calculated value of UCS, indicating that the marbles from the Markhu Formation are of good quality and are strong enough to withstand the load, contributing to rock mass quality. The marbles have extremely high second cycle SDI (Id2) of 98.92% to 99.50%, and therefore, a high resistance to the wetting and drying cycle, showing slow slaking behavior. Between the second and the fifth cycle, SDI (Id5) was deduced by about 1%. It implies that the marbles are highly resistant to weathering and erosion. Marble shows two kinds of disintegration after the second cycle and deteriorates under three types of patterns under five cycles.

Imbibition models quantifying interfacial interactions: Based on nuclear magnetic resonance investigation and coupled structural characteristics

An investigation into spontaneous imbibition in porous media is of paramount scientific significance in various projects. However, a precise understanding of the interaction mechanisms between media structural characteristics and imbibition remains elusive, and quantitative analysis of the interfacial interaction is lacking. Therefore, to mitigate the influence of dispersion, this study first investigates cyclic imbibition experiments of coal samples to explore the interaction mechanism between pore-fracture structure (PFS) and imbibition. Nuclear magnetic resonance is used to visualize water transport during imbibition across all scales. Subsequently, the slake durability index is suggested to clarify the coupling relationship between water–coal interactions and imbibition. Two more comprehensive and accurate imbibition models are established, based on pore size and comprehensive seepage parameters, respectively. The results demonstrate that both new models exhibit superior conformity with experimental data compared to traditional models. The memory factor quantifies interface interaction within these models. Sensitivity analysis reveals that strong interface interaction diminishes the effective imbibition ratio, while the structural characteristics of porous media significantly influence the interaction. Furthermore, the fractal dimension quantitatively characterizes the PFS features of coal samples. An exploration of the relationship between fractal dimension and memory factor indicates the influence of porous media heterogeneity on imbibition.

A study on influential rock properties for predicting the longitudinal wave velocity in a rock bolt: Numerical and machine learning approaches

The longitudinal wave velocity (vL) in a rock bolt is a useful parameter for evaluating the conditions of the rock bolt and the surrounding rock mass. This study investigated the influence of rock properties on the prediction of vL in a rock bolt using numerical and machine learning approaches. Through numerical simulations, we obtained a dataset of the variations in vL according to rock properties, compressional wave velocity (vp), shear wave velocity (vs), density (ρ), Poisson's ratio (μ), porosity (η), uniaxial compressive strength (UCS), and slake durability index (ISD). This dataset was used to design a deep neural network, and the predicted vL was correlated with rock properties. Notably, vL is strongly correlated with vp, vs, ρ, η, UCS, and ISD. Principal component analysis was employed to characterize the relationship between the rock properties, and the retaining rock properties for random forest (RF) were determined. In the RF, the variable importance (VI) of rock properties was assessed. In particular, vs emerged as the most significant predictor of vL. However, relying on vs to predict vL is not sufficient because it accounts for approximately 60–70 % of the VI. For a more reliable prediction of vL, it is essential to incorporate both vs and vp, which collectively account for approximately 80 % of VI. Notably, the VI of physical properties (vp, vs, ρ, and η) accounts for more than 90 %, implying that these properties can be effectively used to predict vL even in the absence of data concerning mechanical properties.

Slake durability indices of shales from the Batu Arang Beds, Selangor Darul Ehsan

The Eocene to Oligocene Batu Arang Beds outcrop within an approximately triangular basin covering some 15 km2 and comprise stiff, structureless clays to well laminated and fissile shales inter-bedded with fine to coarse sandstones and several coal layers. The shales are often silty and even sandy and contain abundant carbonaceous material. The coal mostly occurs as thin laminae, though two thick seams, mined by open-cast and under-ground methods from 1915 to 1960, are found in the eastern part of the basin. To determine the weatherability characteristics of the shales, three samples (A, B and C) were collected at the western wall, and one sample (D) at the eastern wall, of an open-cast shale pit. Samples A and D are located some 10 m, and 5 m, below the ground surface, whilst samples B and C are 10 m, and 16 m, stratigraphically below sample A. Samples A, B and C, and D have average dry unit weights of 16.64, 14.49, and 15.40, kN/m3 and average apparent porosities of 26.2%, 35.7% and 31.7%, respectively. Slake durability indices of all samples for one standard cycle of wetting and drying (Id1) are between 98.3% and 99.3%, and for two standard cycles (Id2), between 96.7% and 98.9%. Durability indices for three standard cycles (Id3) are between 95.1% and 98.2%, and for four standard cycles (Id4), between 93.3% and 97.6%. The indices lead to the conclusion that the shales are of high to extremely high durability and suitable for use as highway embankment or construction material. The high durability classification is supported by recent excavations at an overburden dump where relatively fresh shale blocks with little disaggregation or disintegration are exposed even after being buried for 78 to 85 years.

Investigation of the Disintegration Characteristics of Neogene Mudstone at Different Burial Depths

The complex structure of Neogene mudstone plays an important role in geological disasters. A close relationship exists between the mechanisms of mudstone landslides and the disintegration characteristics of rocks. Therefore, understanding the disintegration characteristics of Neogene mudstone at different depths is crucial for enhancing engineering safety and assessing landslide stability. This study employed Neogene mudstone from different depths to perform disintegration and plastic limit experiments and revealed the sliding mechanisms of landslides involving Neogene mudstone, providing theoretical support for mitigating mudstone geological disasters. Our results demonstrate that Neogene mudstone from different depths experiences varied stress conditions and pore water pressure due to geological actions, significantly affecting the disintegration characteristics. By ignoring the factors of the slip surface, the slake durability index of mudstone decreases with increasing burial depth, while the plasticity limit index tends to rise. The influence of groundwater, geo-stress, and pore structure on Neogene mudstones at different depths results in overall weak stability and disintegration. Landslide occurrences are likely connected to the mechanical properties of mudstones at the slip surface, where a low slake durability index and higher plasticity index make the mudstones prone to fracturing, breaking, and disintegrating once in contact with water.

Su bazlı kopolimer uygulaması ile tüflerin suda dağılmaya karşı duraylılık indeksi değerlerinin iyileştirilmesi

Tuff has been used as a natural building stone in the construction industry since the earliest times. Tuff is slight, simple to manufacture, and has good isolation qualities, which is why it is used so frequently despite its low strength characteristics and high porosity. In this study, samples of white and pink tuff from the regions of Derbent and Gümele districts of Eskisehir province were treated with a water-based (water-soluble) copolymer bath to evaluate their endurance to atmospheric conditions. Spherical samples were subjected to 30-minute slake durability index testing in a water-based copolymer bath. The index values of the initial spherical samples were contrasted with the index values from the fourth cycle of the spherical samples that had received the copolymer bath treatment. Although the index values of the original spherical samples were determined to be 92.22% and 95.32%, respectively, the index values of the spherical sample sets treated with a water-based copolymer bath were determined to be 98.29% and 98.83%, respectively. The study results indicate that spherical samples with a water-based copolymer bath treatment had a greater impact on improving the slake durability index values compared to spherical samples without treatment.

Evaluation of slake durability for carbonaceous rocks exposed to water soaking using electrical resistivity

The present study investigated the electrical conduction and slake durability behaviors of carbonaceous rocks subjected to water soaking. Several series of electrical resistivity and slake durability tests were conducted on carbonaceous rocks with different mineralogical characteristics to explore the intrinsic connection between these two property indexes. Based on the experimental data, a new empirical model was developed to estimate slake durability index of carbonaceous rocks at varied soaking times. The results showed that the clay minerals content of investigated carbonaceous rocks ranged from approximately 20 % to 50 %. The clay minerals are beneficial in enhancing the electrical conduction of carbonaceous rocks, but impose a negative impact on the slake durability, attributing to their superior performance of hydrophilicity and swelling. Electrical resistivity decreased sharply with increasing soaking time within the first 8 days and then it achieved a stable state as soaking time further increased, which was mainly due to the completion of pore saturation and salts/minerals dissolution. The slake durability index exhibited similar evolution characteristics to those of electrical resistivity, which deteriorated sharply to a low or very low level after soaking for 16 days. The clay minerals experienced water absorption and mineral expansion during the first 8 days soaking, leading to the development of micro-cracks that facilitates water intrusion and accelerates the slake durability deterioration. These two processes were essentially complete as the soaking time further increased, and the clay minerals played an insignificant role at this stage. Liner increasing trends were observed in the plot of electrical resistivity decrease versus slake durability index decrease, and the slope values presented a power function relation with the clay minerals content of carbonaceous rocks. The proposed empirical model well captured the trends in the experimental data, with an absolute difference in percentage δ below30 % and a root mean square error RMSE value of 5.613 %. The outcomes of this study provided a viable answer to assess slake durability of carbonaceous rocks exposed to adverse external environments using non-destructive testing techniques.

Experimental study on deterioration of bedrock strength and P-wave velocity by pressurized seawater

Bedrock has to be excavated before the construction of rock-socketed pile foundations for offshore wind power turbines, leading to the exposure of fresh and dry rocks to seawater. The pile-rock interface is partially separated under the long-term action of various cyclic loads during the operation stage of offshore wind turbines, and the infusion of seawater will further weaken the bedrock. To comprehensively investigate the deterioration of bedrocks by pressurized seawater, tests on point load strength and slake durability were carried out to study the long-term deterioration of mechanical properties of granite, sandstone, and tuff collected from an offshore wind power farm. The elastic P-wave velocity was measured to analyze the variation trend of P-wave velocity, the mechanism of which was revealed by means of Gassmann’s equation. The results of mechanical experiments indicate that granite is almost impervious to pressurized seawater, while the mechanical properties of sandstone and tuff are deteriorated by water, especially by the pressurized seawater. After 60 days of immersion in seawater at 0.5 MPa pressure, decreasing amplitude of point load strength and slake durability index for the sandstone specimens in seawater reaches 53.2% and 18.5%, respectively, and that for the tuff specimens is 14.6% and 1.52%, respectively. The elastic P-wave velocity of granite shows an upward trend with increasing immersion time in different environments, but there exists a different tendency between the P-wave velocity of sandstone and tuff specimens in water or seawater with normal pressure and that in seawater with 0.5 MPa pressure. The variation of P-wave velocity of different types of rocks is studied based on Gassmann’s equation that takes into account the change of saturation degree, porosity, and compressibility of the matrix material.

Use of Coal Mine Overburden as Sustainable Fine Aggregate in Cement Mortar

The natural aggregate crisis is an alarming concern for the construction industry worldwide. This study provides a detailed investigation of coal mine overburden (OB) from opencast mine dumps, to evaluate its potential as a sustainable alternative to natural aggregate. The microproperties, including mineralogy, morphology, and chemistry, were evaluated, and the macroproperties, including alkali–aggregate reaction, soundness, durability, flow value, ultrasonic pulse velocity, and other mechanical properties of crushed OB, OB-based mortar, and concrete, were determined. OB was found to be mineralogically more stable (55%–77% SiO2), mechanically comparable, and durable (volume change 3%–8%) than other alternatives of natural aggregate. The toxicity characteristic due to leaching was found to have no hazardous effects on local and regional soil and water quality. The cement mortar prepared using OB had similar performance in terms of fresh and hardened density, flowability (>0.6 w/c), and durability [slake durability index (SDI) >95%] as other industrial by-products. The compressive strength of the mortar with OB was found to be comparable to that of mortar with river sand. OB-based mortar and concrete were found to have good corrosion resistance. For bulk utilization of OB, a pilot-scale study is recommended to assess its performance under real-world exposure conditions.

Strength and durability status of the Fagfog Quarzite from the Lower Nawakot Group, central Nepal Lesser Himalaya

Railways have played vital role in the development of many countries worldwide. Government of Nepal has already planned to establish various national and international railway networks within the nation. A substantial quantity of durable rock ballasts is required for building a sustainable railway network. Quartzites from central Nepal Lesser Himalaya can be a promising source to fulfill this requirement. Therefore, the quartzites from the stratigraphic unit Fagfog Quartzites of the Lower Nawakot Group located in Dhading District along the Kalu Pandey Highway have been assessed to determine physical, strength and durability characteristics of the ballasts. All quartzite ballasts obtained from the bedrocks were of Precambrian, medium-grained, bladed to prolate shaped, white to brownish white, crushed quartzites. Dry density and water absorption were respectively 2336-2641 kg/m3 and 0-2.5%. The bulk density varies from 1204 and 1387 kg/m3. Point load strength index varies from 2.04 to 11.55 MPa (medium strong to extremely strong). Aggregate Impact Value (AIV) and Aggregate Crushing Value (ACV) ranges from 14.85 to 22.77% and 15.51 to 22.17% respectively. Some 7% results of AIV and 20% of ACV results exceeded the established limiting value of 22%. The slake durability index (Id5) ranges from 95.19 and 99.11%, whereas Id2 ranged between 96.94 and 100%, which shows that 80% of the samples have very high slake durability whereas remaining 20% exhibit high slake durability. There was no significant change in slake durability index from the second to the fifth cycles. Los Angeles Abrasion Value (LAAV) varies from 12.07 to 31.34% and Sulphate Soundness Value (SSV) varies within a limited range of 0.20 and 4.59%. Conclusively, the comprehensive evaluation suggests that the quartzite ballast from the Fagfog Quartzite source display favourable qualities in terms of point load, crushing and impact strengths and durable against abrasion, slaking and frosting. Thus, the quartzites from Fagfog Quartzite hold significant potential as a suitable rock type for railway track ballasts.

On the importance of specimen’s geometric shape effects on the slake-durability index of limestones and grain size distribution of the sediment particles obtained during the test

The slake-durability test is one of vital test method used in engineering geological studies for evaluating resistant of rocks against wetting–drying cycles in humid environments. The result of the test is related to many parameters specially specimen’s geometric shape. In the present research, eight limestone samples used as common building stones in Iran have been selected and their mineralogical and physical properties have been measured in the laboratory. In order to determine the effect of specimen’s shape on the slake-durability index of the stones, laboratory specimens were prepared in seven various shapes including lump, rounded lump, cube, sphere, square prism, square-base plate, and rectangular cube which have different shape parameters. After performing the slake-durability tests, the samples were classified as very durable rocks according to Gamble and Franklin-Chandra classifications. The results indicated that specimen’s shape has essential effects on both rock durability and grain size distribution of the obtained sediment particles, so that the spherical and lump specimens shown the highest and lowest values of the slake-durability index, respectively. This means that more unregular dimensions, nonsphericity, and angularity of the specimens lead to decrease the slake-durability index which is highly correlated to the roundness (Rc) values of the specimens. The granulation parameters (D10, D30, D60, Cu, and Cc) of the obtained sediment particles were different for the tested samples. These parameters were recognized related to the specimen’s shape so that, the D60 and Cu are also highly correlated to the roundness (Rc) values of the specimens used in the slake-durability test.

Slake durability index (SDI) of weathered Deccan trap basalt

The slake-durability test is considered to be a basic method for determining the degree to which a rock is susceptible to the effects of the weather. The results of this experiment shed light on the processes that take place when rocks are exposed to the elements at varying depths or even on the surface of the earth. During the slake-durability tests, Franklin and Chandra said that ion exchange and capillary tension are applied to the mechanisms. A total of ten rock samples gathered from a variety of locations were subjected to slake durability testing in order to ascertain the degree to which the Deccan trap basalt is susceptible to the elements in the vicinity of Indore (Madhya Pradesh). It is possible that the dry operation will only take forty-five minutes to complete for some basalt rocks, namely the surface region of the basalt samples.

Effects of groundwater and distilled water on the durability of evaporitic rocks

Evaporitic rock durability induced by groundwater cause several construction challenges, but representative experimental studies to evaluate such conditions are still missing. Therefore, this study intended to provide better and more realistic degradability features of evaporites with groundwater besides a comparison with distilled water as slaking fluids. Forty-eight evaporitic rock blocks were collected from Abu Dhabi area, United Arab Emirates. 96 slake durability index (SDI) tests were performed, 48 with each of the slaking fluids; groundwater and distilled water, and their textural, mineralogical, and geochemical attributes were also examined before and after the SDI tests. In comparison to mineralogical and textural modifications, slaking fluid had a greater impact on the chemical composition of evaporitic rock. The study shows that the degradability of evaporites with groundwater and distilled water indicates a wide range from very low to high. The mean weight loss values after four cycles with groundwater and distilled water vary from 11 to 77 and from 4 to 81 wt.%, respectively. Consequently, slaking with groundwater illustrates a wide range compared to the slaking with distilled water. This could be due to quick interactions between groundwater and evaporites and fast hydration-dehydration process than distilled water due to the chemical composition of the groundwater. It is recommended to investigate the attributes of evaporitic rocks as well as groundwater geochemistry for safe, cost-effective, and sustainable structures.

EVALUATION OF GEOTECHNICAL PROPERTIES AND PETROGRAPHIC CHARACTERISTICS OF SANDSTONE, BAGH AREA, AZAD JAMMU AND KASHMIR, PAKISTAN

Sandstones are abundant in the regions of Azad Jammu and Kashmir in northeastern Pakistan. However, physio-mechanical data for project planning and construction of these sandstones, which serve as aggregates and foundations for a variety of infrastructures, are lacking. This research aims to investigate the petrographic and physio-mechanical characteristics of Murree and Kamlial Formation sandstones in the Rawalpindi group. The physio-mechanical parameters included specific gravity, water absorption, unconfined compressive strength (UCS), slake durability, Ultrasonic pulse velocity (UPV), and Brazilian. The findings suggest that the sandstone of the Murree and Kamlial formations can be classified as construction-grade rocks. A comprehensive analysis of physico-mechanical observations of these sandstones shows a statistically significant correlation with point load index, Brazilian tensile strength, and UPV in a saturated condition against unconfined compression strength (UCS). Whereas the specific gravity, water absorption, slake durability index, and UPV in dry conditions found no statistically significant correlation against UCS. By rigorous petrographic research, the texture of quartz %, mineralogy and mineral alteration, the existence of micro-fractures, and mineral size distribution all contribute to the total strength qualities of these sandstones. To comprehend the suitability of Muree and Kamlial Formation sandstones, physio-mechanical characteristics were then correlated with the sequence (Murree sandstone) exposed at the Jena Kor village in Peshawar Basin. Based on the results, the sandstones of the Murree and Kamlial Formations in the study area are found appropriate for construction.

Soft computing approaches for evaluating the slake durability index of rocks

Soft computing approaches for evaluating the slake durability index of rocks