scholarly journals CORRELATION BETWEEN UNCONFINED COMPRESSIVE STRENGTH AND INDIRECT TENSILE STRENGTH FOR JOINTED ROCKS

2016 ◽  
Vol 05 (05) ◽  
pp. 157-161 ◽  
Author(s):  
N.Kabilan .
Author(s):  
Louay N. Mohammad ◽  
Amar Raghavandra ◽  
Baoshan Huang

In-place cement-stabilized soils have served as the primary base material for the majority of noninterstate flexible pavements in Louisiana for many years. These materials are economically and easily constructed and provide outstanding structural characteristics for flexible pavements. However, these cement-treated materials crack due to shrinkage, with the cracks reflecting from the base to the surface. A laboratory study examined the performance of four different cement-stabilized soil mixtures recently used in the construction of test lanes at the Louisiana Pavement Testing Facilities. Laboratory tests included the indirect tensile strength and strain, unconfined compressive strength, and indirect tensile resilient modulus tests. The four mixtures were ( a) in-place-mixed cement-treated soil with 10 percent cement, ( b) plant-mixed cement-treated soil with 10 percent cement, ( c) plant-mixed cement-treated soil with 4 percent cement, and ( d) plant-mixed cement-treated soil with 4 percent cement and fiber reinforcement. The results indicated that there was no significant difference in performance between the plant-mixed and in-place-mixed cement-treated soil mixtures. The inclusion of fiber to the cement-treated soil mixture significantly increased the indirect tensile strain and the toughness index. Increases in compaction effort maintained or significantly increased the indirect tensile strength and unconfined compressive strength. Increases in curing period maintained or significantly increased indirect tensile and unconfined compressive strength as well as the resilient modulus of the mixtures.


2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Mohd Rosli Hainin ◽  
Mohd Yazip Matori ◽  
Oluwasola Ebenezer Akin

Over recycling of asphalt pavements involves mixing of existing pavement material with stabilizing agent such as foamed bitumen, bitumen emulsion, cement or lime and placed on the milled pavement and compacted. The strength of foamed bitumen stabilized mix is influenced by factors such as cement content, moisture level and curing time. It was found that the strength in terms of resilient modulus, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) values, increased with curing time and percentage of active filler. It was also found that the maximum strength in terms of resilient modulus, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) was not at Optimum Moisture Content (OMC) and the strength decreased as the RAP proportion increased


Teknika ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. 48
Author(s):  
Donny Ariawan ◽  
Slamet Budirahardjo ◽  
Ikhwanudin Ikhwanudin

Jalan beraspal merupakan salah satu prasarana transportasi utama di Indonesia yang belum sepenuhnya mencapai kondisi yang aman dan nyaman dimana sering dijumpai kondisi permukaan jalan yang tidak rata, bergelombang dan berlubang yang menyebabkan ketidaknyamanan bagi penggunanya. Kegiatan perbaikan dan pemeliharaan struktur perkerasan jalan, dalam hal ini jalan beraspal, menjadi sangat penting untuk kelangsungan kegiatan transportasi. Pesatnya perkembangan teknologi di bidang transportasi telah melahirkan satu terobosan baru tentang teknologi penanganan kerusakan jalan yaitu dengan cara daur ulang lapis perkerasan aspal yang sudah ada. Metode daur ulang ini memiliki keuntungan antara lain dapat menghemat biaya, merupakan green technology, memiliki kualitas yang sama dengan material baru, dan menjaga geometris perkerasan karena tebal perkerasan yang sama. Penentuan kadar air terbaik dalam campuran foam bitumen terhadap nilai kuat tarik tak langsung (ITS) serta kuat tekan bebas (UCS) untuk campuran lapis pondasi daur ulang. Dilakukan secara bertahap, dari pengujian untuk bahan penyusun campuran yaitu agregat baru, Reclaimed Asphalt Pavement (RAP), filler, aspal, dan foam bitumen. Kemudian uji terhadap campuran padat meliputi Uji Marshall, Uji Indirect Tensile Strength (ITS) dan Uji Unconfined Compressive Strength (UCS). Kadar air dan kadar foam bitumen sangat berpengaruh terhadap kuat tarik tak langsung (Indirect Tensile Strength/ITS) serta kuat tekan bebas (Unconfined Compressive Strength/UCS) dari campuran dingin daur ulang dengan foam bitumen. Nilai ITS, TSR dan UCS yang dicapai menggunakan kadar foam 2% dan kadar air optimum terbaik yang diketahui dalam penelitian sebesar 100% terhadap Kadar Air Optimum (KAO) yaitu masing- masing 301,04 kPa, 76,36%, dan 723,49 kPa


2018 ◽  
Vol 13 (4) ◽  
pp. 447-474 ◽  
Author(s):  
Ali Ghorbani ◽  
Maysam Salimzadehshooiili ◽  
Jurgis Medzvieckas ◽  
Romualdas Kliukas

In this paper, stress-strain behaviour of sand-clay mixture stabilised with different cement and rice husk ash percentages, and reinforced with different polypropylene fibre lengths are evaluated. Mixtures are widely used in road construction for soil stabilisation. It is observed that replacing half of the cement percentage (in high cement contents) with rice husk ash will result in a higher unconfined compressive strength. In addition, the presence of 6 mm polypropylene fibres will help to increase the unconfined compressive strength of stabilised samples, while larger fibres cause reverse behaviour. In addition, introducing a new index for assessing the effect of curing days. Curing Improvement Index it is obtained that larger fibres show higher Curing Improvement Index values. Results gained for the effects of curing days, and fibre lengths are further discussed and interpreted using Scanning Electron Microscopy photos. Based on the conducted Unconfined Compressive Strength, Indirect Tensile Strength, and Flexural Strength tests and using evolutionary polynomial regression modelling, some simple relations for prediction of unconfined compressive strength, indirect tensile strength, and flexural strength of cement-rice husk ash stabilised, and fibre reinforced samples are presented. High coefficients of determination of developed equations with experimental data show the accuracy of proposed relationships. Moreover, using a sensitivity analysis based on Cosine Amplitude Method, cement percentage and the length of polypropylene fibres used to reinforce the stabilised samples are respectively reported as the most and the least effective parameters on the unconfined compressive strength of specimens.


Author(s):  
Mohammadreza Kamali ◽  
Mahmoud Khalifeh ◽  
Arild Saasen ◽  
Laurent Delabroy

Abstract Integrated zonal isolation is well-known as a key parameter for safe drilling operation and well completion of oil and gas wells. An extensive research on alternative materials has been conducted in the past concerning primary cementing, overcoming annular leaks, and permanent well abandonment. The present article focuses on geopolymers, expansive cement, pozzolan based sealant and thermosetting resins. The viscous behavior and the pumpability of the different materials have been investigated and benchmarked with the properties of neat class G Portland cement. The current study includes short-term mechanical properties of the above-mentioned materials. These properties include compressive strength development, Young’s modulus, indirect tensile strength, and sonic strength. The tests are performed in accordance with API 10B-2 and ASTM D3967-16 for all the materials for 1, 3, 5, and 7-day of curing at 90°C and elevated (172 bar) and atmospheric pressures. Our results show a mixed behavior from the materials. According to uniaxial compressive test results, all the candidate barrier materials developed strength during the considered period; however, the geopolymer and pozzolanic-based mixture did not develop early strength. The expansive cement showed an acceptable early compressive strength, but strength reduction was noticed after some time. The strength reduction of expansive cement was also observed for the indirect tensile strength. All the materials become stiffer overtime as they made more strength. For the neat class G cement and expansive cement, the Young’s modulus showed a minimum after 5 days, but it was increased.


2018 ◽  
Vol 67 (4) ◽  
pp. 83-94
Author(s):  
Grzegorz Rogojsz ◽  
Damian Skupski ◽  
Bartosz Januszewski

This paper presents the results of laboratory tests on the properties of cement concrete containing various types of aggregate. The purpose of the tests was to determine the effect of aggregate on compressive strength, indirect tensile strength, air pore characteristics, frost resistance and the modulus of elasticity of concrete for road surfaces. The aggregate that meets the requirements for road concrete was determined on the basis of the tests. Keywords: road concrete, frost resistance of aggregate, frost resistance of road concrete.


2018 ◽  
Vol 12 (1) ◽  
pp. 441-457 ◽  
Author(s):  
Sahar Jabbar Alserai ◽  
Wissam Kadhim Alsaraj ◽  
Zina Waleed Abass

Introduction:One of Iraq’s major environmental problems is a large amount of residual iron produced by the industrial sector, which is stored in domestic waste and landfills. The reuse of construction waste gives two aims, the first is to remove large quantities of pollution resulted from these waste, the second provides cheap resources for concrete aggregates.Methods:This study conducted a series of experiments and tests to test the feasibility of reusing this iron slag and recycled concrete aggregate in concrete mixtures. Different percentages of iron filings were used in the concrete mixture at 0, 0.5%, 0.75% and 1%. Tests are done to evaluate the quality of cast iron concrete which include compressive strength (fcu), flexural strength (fr), indirect tensile strength (ft), SEM and modulus of elasticity (Ec) for four sustainable concretes.Results and Conclusion:The results show that the iron filings amount is increased to 1.0% which resulted in increasing percentage of compressive strength (fcu), flexural strength (fr), indirect tensile strength (ft), SEM and modulus of elasticity (Ec) with 10%, 32%, 42% and 11% for Geopolymer Concrete with Recycled Aggregate (GCRA), 9%, 52%,31% and 17% for geopolymer concrete with natural aggregate (GCNA), 10%, 19%,26% and 12% for Normal Concrete with Natural Aggregate (NCNA) and 23%, 19%, 67% and 14% for Normal Concrete with Recycled Aggregate (NCRA), respectively.


2013 ◽  
Vol 723 ◽  
pp. 466-473 ◽  
Author(s):  
Jia Chong Du ◽  
Ming Feng Kuo ◽  
J.C. Yeh

This study focused on the properties of the cement asphalt emulsion (CA) mortar. The mixtures of the samples were fabricated and allowed them seven, fourteen and twenty eight days for curing before tested by compressive strength, three points flexural test, and indirect tensile strength to probe into their engineering properties. Hydraulic cement mortar samples used as control are analyzed for comparison. The test results show that the compressive strength is hydraulic cement mortar greater than CA mortar; the flexural strength at curing of 28 days is CA mortar greater than hydraulic cement mortar, however, at curing of 7 and 14 days is hydraulic cement mortar greater than CA mortar; and the indirect tensile strength is hydraulic cement mortar greater than CA mortar. The Scanning Electron Microscope (SEM) analysis results show that the Ca (OH2) increased with increases curing time. The CA mortar samples fabricated needs appropriate water for lubrication. Thus, the water absorption of fine aggregate must be concerned. The emulsion asphalt added too much may reduce the strength. In field test, the CA mortar performs very well, especially in workability.


2013 ◽  
Vol 59 (2) ◽  
pp. 175-195 ◽  
Author(s):  
Nageh N. Meleka ◽  
Alaa A. Bashandy ◽  
Mohamed A. Arab

Abstract In this research reactive powder concrete (RPC) was prepared using sand from North Sinai. The mechanical properties of locally cast RPC were investigated and evaluated by studying the effects of using different cement and silica fume contents and new steel fibers’ aspect ratios as reinforcement for RPC. Specimens’ preparation, curing regimes and testing procedures to evaluate the compressive strength, the modulus of elasticity, the indirect tensile strength and the flexural strength were discussed. A compressive strength of 154.5MPa, indirect tensile strength of 11.98MPa, modulus of elasticity of 45.1GPa and flexural strength of 30.26MPa have been achieved for reinforced RPC contains 800 kg/m3 cement content and silica fume content 30% of cement weight. The test results showed some improvements by increasing cement and silica fume contentsas well as adding steel fibers on the compressive strength, modulus of elasticity and indirect tensile strength.


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