Evaluation of strength and durability of rocks from Malekhu-Thopal Khola area, Central Nepal Lesser Himalaya for construction aggregates

Abstract

Aggregate, the inert materials used in almost every field of modern development structures have great influence. Aggregates may look similar in appearance but they may carry different physical, mechanical and chemical properties and they may perform accordingly. End uses of aggregates are also determined by their performance. The Lesser Himalaya of the Malekhu- Thopal area comprises more than 14 formations having great potential of rock aggregates. The present study was carried out in order to reveal the toughness and soundness of each rock type of the Lesser Himalaya so that durability can be determined. Altogether 25 representative samples were tested to find porosity, specific gravity, dry density, uniaxial compressive strength (UCS), Los Angeles abrasion value (LAAV), aggregates impact value (AIV), sodium sulphate soundness Value (SSSV), ethylene glycol soaking value and water absorption value (WAV). Results were compared with standards of different specifications and recommended for wide range end uses.Rock mass rating of each formation was carried out and the value ranges from 36 to 82. Specific gravity ranges from 2.08 to 3.08 and the dry density ranges from 2.3 to 3.22 g/cm3. All the samples have porosity less than 2% except the samples of the Benighat Slate. UCS value ranges from 5.9 to 301.9 MPa. The LAAV of the sample lies between 19.6% and 47.5%. AIV is between 8.54% and 34.28%. The SSSV ranges from 2.35 to 26.06%. Ethylene glycol soak index is 2 of all samples signifying that proportion of swelling clays or low accessibility of ethylene glycol through the samples due to low porosity. WAV of all the samples is below 2% except the Benighat Slates which indicates that the aggregates have low effective porosity. The entire test shows that most of the sample meets different national and international standards and can be recommended for wide range of end uses.Bulletin of the Department of Geology, Vol. 18, 2015, pp. 15–34

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

“…The majority of the samples fall into the acceptable limit of <35% suggested by AREMA (2009). Point-load strength index of the Fagfog Quartzite varies within a wider range compared to the results of the earlier studies (Bista and Tamrakar, 2015;Tumbapo, 2016). UCS of the current study is wider in range compared to the range obtained by Bista and Tamrakar (2015).…”

“…Point-load strength index of the Fagfog Quartzite varies within a wider range compared to the results of the earlier studies (Bista and Tamrakar, 2015;Tumbapo, 2016). UCS of the current study is wider in range compared to the range obtained by Bista and Tamrakar (2015). Majority of quartzites gave less than 150 MPa except of higher values around 300 Mpa (Adom-Asamoah et al, 2014;present study, Table 9).…”

“…Gupta and Sharma (2012) investigated quartzites from the northwest Himalayas and came to the conclusion that texture and rock strength were closely correlated. Quartzites are one of the most strong and durable rock types (Maharjan and Tamrakar, 2007;Bista and Tamrakar, 2015). They are therefore suitable rock types for construction aggregates and stones because they perform well under severe weathering environment and heavy load.…”

Effects of long-term magnesium sulfate crystallisation tests on abrasion and durability of andesite aggregates

“…The monotony of the alteration of the weight loss is also observed in the case of long-term freeze-thaw weathering tests of limestone, granite and lapilli tuff (Ruedrich et al 2004). Bista and Tamrakar (2015) measured the weight loss of several rock types after every cycle of the magnesium sulfate test and found that weathering could be detected in all cases causing weight loss. The long-term weathering properties of the rocks can be analysed by the repeat of the weathering effects such as freeze-thaw cycles of sulfate crystallisation tests.…”

Field-based assessment of rock discontinuity and geological attributes of rock mass for stones for various engineering applications

“…Quartzite samples of the Robang Formation (RF-QZT1 and RF-QZT2) and of the Chisapani Quartzite (CQ-QZT3) have more or less similar mineralogical composition but they have varying strength values due to their textural characteristics (Kheirelseed et al, 2008;Bista and Tamrakar, 2015). RF-QZT1 and RF-QZT2 differ in textural properties but these samples have same strength range due to presence of sericite minerals in RF-QZT1.…”