scholarly journals Petrographic and Geotechnical Characteristics of Carbonate Aggregates from Poland and Their Correlation with the Design of Road Surface Structures

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2034
Author(s):  
Jerzy Trzciński ◽  
Emilia Wójcik ◽  
Mateusz Marszałek ◽  
Paweł Łukaszewski ◽  
Marek Krajewski ◽  
...  

The paper presents the basic problem related with practical application of carbonate rocks in construction: are carbonate aggregates produced from such rocks favorable for building engineering, particularly for road design and construction? To resolve this problem, (1) the geological-engineering properties of aggregates are presented, (2) the correlation between petrographic and engineering parameters is shown, and (3) a strict correlation between the geological-engineering properties and the freezing-thawing and crushing resistance is recognized. This knowledge has allowed to assess the usefulness of asphalt concrete (AC) made from dolomite and limestone aggregates in the design and construction of road surface structures. The petrography was characterized using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscope (EDS). Engineering properties were determined in accordance with European and Polish norms and guidelines. Statistical and design calculations were performed using dedicated software. The petrographic properties, and selected physical and mechanical parameters of the aggregates, were tested to show their influence on the freezing–thawing and crushing resistance. Strong functional relationships between the water adsorption, and the freezing–thawing and crushing resistance have been observed. Aggregate strength decreased after saturation with increasing concentrations of salt solutions. Calculations of AC fatigue durability and deformation allow for reducing the thickness of the road surface structure by about 20% in comparison to normative solutions. This conclusion has impact on the economy of road design and construction, and allows for a rational utilization of rock resources, which contributes to sustainable development of the construction industry.

The aim of the present study is to determine the physical and geotechnical characteristics of municipal solid waste (MSW) from an open dump site located in Una town, Himachal Pradesh (India) for the analysis of settlement and structural stability of landfill. Degraded waste was tested for different time intervals ranging from 6 months to 6 years. The physical characterization and the geotechnical tests were performed to determine the composition and the engineering properties of MSW respectively. The presence of moisture content in the fresh waste was 49.5±1.05% but for the degraded (or old) waste it varied between 39.8 to 51.6%. The specific gravity of fresh and old waste varied between 1.83±0.05 and 1.85 for 6 months old waste and 2.28 for 5-6 years old degraded waste respectively. The maximum dry density (MDD) was observed to be 4.28 kN/m2 for fresh waste at the optimum moisture content (OMC) of 78.1% and 4.47 kN/m3 for 6 months old waste and 6.25 kN/m3 for the degraded waste of 5-6 years at 80.2, 85.4% of OMC respectively. The hydraulic conductivity (k) of MSW was found to be decreasing with the degradation of MSW and the overburden pressure whereas the shear strength increased along with the degradation of the waste. The cohesion (c) and angle of internal friction (φ) increased respectively from 31.2 kPa(fresh) to 38 kPa(degraded) and 14° to 22° with the increase in waste degradation. The compression ratio of fresh waste was within the ranges of 0.19-0.29 and for degraded MSW it varied between 0.12 for 6 months old waste and 0.17 for 5-6 years old degraded waste respectively.


2021 ◽  
Author(s):  
Khalil Khaska ◽  
Dániel Miletics

AbstractNowadays, self-driving cars have a wide reputation among people that is constantly increasing, many manufacturers are developing their own autonomous vehicles. These vehicles are equipped with various sensors that are placed at several points in the car. These sensors provide information to control the vehicle (partially or completely, depending on the automation level). Sight distances on roads are defined according to various traffic situations (stopping, overtaking, crossing, etc.). Safety reasons require these sight distances, which are calculated from human factors (e.g., reaction time), vehicle characteristics (e.g., eye position, brakes), road surface properties, and other factors. Autodesk Civil 3D is a widely used tool in the field of road design, the software however was developed based on the characteristics of the human drivers and conventional vehicles.


2019 ◽  
Vol 10 (3) ◽  
pp. 22-26
Author(s):  
Abdul Jabbar Khan ◽  
Naveed Ahsan ◽  
Muhammad Sanaullah ◽  
Gulraiz Akhter

Ormara is located 240 km west of Karachi which is a coastal and port city (25° 16' 29N, 64° 35' 10E) ofPakistan. Present study evaluates engineering properties of soils of Ormara for future construction plans and possibleexpansions in the area. Fifty bore holes were done in study area at depths of 20m, 40m and some (10 bore holes) were60m deep. The study area was divided into three major zones i.e. Foot hills, on-shore and off-shore. Groundwater wasencountered at depths of 2.75m on onshore and offshore zones and at 3.65m depth in foothill zone. Laboratory testingi.e. moisture content (12 to 38 %), liquid limit (from 26 to 34), plasticity index (10 to 18) of soil samples indicate thatsoils are low plastic to moderate plastic in nature. Soil samples of granular soils indicate angles of internal friction (ø)varying from 260- 36ºin upper sand layers while 260 to 30º in lower silt layers (encountered after the clay layer) andCohesion ranges 0 to 0.04kg/cm2 in all three zones. Further, unconsolidated undrained triaxial compression tests on aclayey soil sample indicated an undrained cohesion value of 28 kPa. Density values ranges from 1.6 to 2.05gm/cm3.Consolidation (Cv = 0.20 to 0.40 cm2/minute, Cc = 0.149 to 0.17) has been calculated for clay layer. Chemical testscarried out on soil samples indicated that soil and water both are reactive aggressively and may cause corrosion to steeland concrete disintegration.


2011 ◽  
Vol 164 (3) ◽  
pp. 165-179 ◽  
Author(s):  
John Fox ◽  
Donald Bell ◽  
Graham Edmond ◽  
Peter Cummings ◽  
James Langstraat

2013 ◽  
Vol 35 (1) ◽  
pp. 41-57 ◽  
Author(s):  
Aleksandra Borecka ◽  
Bartłomiej Olek

Abstract This work is only a preliminary study on the evaluation of geological engineering properties of loess area of Kraków. It has been expanded to include field tests (CPTU, DMT), which is an alternative to expensive and time-consuming laboratory tests. The field tests allow enough detail to track the variability of physical and mechanical properties of soils, but in many cases, provide too much information, because their interpretation is often based only on a qualitative analysis. Laboratory and field tests are complementary and should be continued in order to determine best the correlation between the measured values of the resistance probes (CPTU, DMT) and the results obtained from laboratory tests. This will provide new calculation formulas for the evaluation of geotechnical parameters of loess in situ.


Author(s):  
Xu-dong Wang ◽  
Guang-li Zhou ◽  
Hai-yan Liu ◽  
Qing Xiao

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