Effect of Coarse Aggregate Columns on Angle of Friction in Fine Sandy Soil

2019 ◽  
Vol 7 (2) ◽  
pp. 55-61
Author(s):  
Haqi H. Abbood Al-Eqabi ◽  
Ali M. Hassan Al-Gharbawe
Keyword(s):  
Critical State ◽  
Void Ratio ◽  
Coarse Aggregate ◽  
Fine Sand ◽  
Friction Angle ◽  
Sand Soil ◽  
Coarse Aggregates ◽  
The Coefficient Of Friction ◽  
River Deposits ◽  
Soil Gradation

Abstract: the study adopted samples from Tigris river shoulders ,which has been subjected to such collapses and cracks. After testing and investigation it was found the soil is formed from river deposits , which can be classified as fine sand soil . It is known that many of the collapses that occurs in the sides of rivers are due to the influence of shear forces . A different of diameters coarse aggregates columns and aggregates sizes used in this study are tested by direct shear test. The main objective of this research to increase the coefficient of friction between the soil particles in the test specimen by adding the coarse aggregate columns to the fine sand soil, In this regard the least void ratio was found as a beneficial index that relates with critical state of friction angle independent on soil gradation. The relations between critical state or high friction angles of the mixture with lower void ratio were determined as a function of addition pressure. The relationships could be useful to determination the strength parameters of (sand gravel mixtures).

scholarly journals Influence of Coarse Aggregate Gradation on the Mechnical Properties of Concrete, Part I: No-Fines Concrete

2019 ◽  
Vol 9 (5) ◽  
pp. 4612-4615 ◽  
Author(s):  
Z. A. Tunio ◽  
F. U. R. Abro ◽  
T. Ali ◽  
A. S. Buller ◽  
M. A. Abbasi
Keyword(s):  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Fine Sand ◽  
Minimum Size ◽  
Unit Weight ◽  
Lightweight Aggregate Concrete ◽  
Total Load ◽  
Aggregate Gradation ◽  
Coarse Aggregates

It is well-accepted fact that in concrete construction, the self-weight of the structure is a major part of its total load. Reduction in the unit weight of the concrete results in many advantages. The structural lightweight aggregate concrete (LWAC) of adequate strength is now very common in use. In frame structures, the partition walls are free of any loading, where the construction of these non-structural elements with lightweight concrete of low strength would lead to the subsequent reduction of the overall weight of the structure. No-fines concrete is one of the forms of lightweight concrete and it is porous in nature. It can be manufactured similarly as normal concrete but with only coarse aggregates and without the sand. Thus, it has only two main ingredients; the coarse aggregates and the cement. The coarse aggregates are coated with a thin cement paste layer without fine sand. This is a detailed experimental study carried on NFC with fixed cement to the aggregate proportion of 1:6 with w/c 0.40 ratio. In this study, coarse aggregate of  various gradations (7-4.75) mm, (10-4.75) mm, (10-7) mm, (13-4.74) mm, (10-7) mm, (13-4.75) mm, (13-10) mm, (13-7) mm, (20-4.75) mm, (20-7) mm, (20-10) mm, (20-13) mm, are used, where prefix and suffix show the maximum and minimum size of the aggregate. The cube and cylinder specimens of standard sizes are cast to determine the compressive strength and splitting tensile and the specimens are cured in water up to the age of testing (28 days).

Influence of Physical Strengthening Technology on the Properties of Recycled Coarse Aggregate

2017 ◽  
Vol 727 ◽  
pp. 1074-1078
Author(s):  
Gong Bing Yue ◽  
Qiu Yi Li ◽  
Gao Song
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Apparent Density ◽  
Void Ratio ◽  
Coarse Aggregate ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Absorption Ratio ◽  
Index Value

This paper studied the properties improvement of recycled coarse aggregate by the physical strengthening technology (particle-shaping method). Through the analysis for obtained properties which consist of density, crush index, bulk density and water absorption. etc of recycled coarse aggregates in different strengthening technologies, the categories of recycled coarse aggregate could be assessed and determined. The results showed that ordinary recycled coarse aggregates that was handled twice by using particle shaping equipment can achieve the standard of class Iaggregates and its water absorption ratio at 24h was 1.2%, the apparent density reached 2575kg/m3, crush index value was 9%, the void ratio was 45%, all property parameters were close to those of natural coarse aggregate.

scholarly journals Effect of Recycled Coarse Aggregate and Bagasse Ash on Two-Stage Concrete

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Material ◽  
Strength Reduction ◽  
Recycled Aggregate ◽  
Two Stage ◽  
Conventional Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

Numerous research studies have been conducted to improve the weak properties of recycled aggregate as a construction material over the last few decades. In two-stage concrete (TSC), coarse aggregates are placed in formwork, and then grout is injected with high pressure to fill up the voids between the coarse aggregates. In this experimental research, TSC was made with 100% recycled coarse aggregate (RCA). Ten percent and twenty percent bagasse ash was used as a fractional substitution of cement along with the RCA. Conventional concrete with 100% natural coarse aggregate (NCA) and 100% RCA was made to determine compressive strength only. Compressive strength reduction in the TSC was 14.36% when 100% RCA was used. Tensile strength in the TSC decreased when 100% RCA was used. The increase in compressive strength was 8.47% when 20% bagasse ash was used compared to the TSC mix that had 100% RCA. The compressive strength of the TSC at 250 °C was also determined to find the reduction in strength at high temperature. Moreover, the compressive and tensile strength of the TSC that had RCA was improved by the addition of bagasse ash.

scholarly journals Influence of coarse aggregate on shear resistance of self-consolidating concrete beams

2017 ◽  
Vol 10 (1) ◽  
pp. 30-40
Author(s):  
G. SAVARIS ◽  
R. C. A. PINTO
Keyword(s):  
Shear Strength ◽  
Failure Modes ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Self Consolidating Concrete ◽  
Coarse Aggregates ◽  
Lower Shear ◽  
Nominal Size ◽  
High Flowability

Abstract Self-consolidating concrete is characterized by its high flowability, which can be achieved with the addition of superplasticizer and the reduction of the amount and size of coarse aggregates in the concrete mix. This high flowability allows the concrete to properly fill the formwork without any mechanical vibration. The reduction in volume and particle size of the coarse aggregates may result in lower shear strength of beams due to a reduced aggregate interlock. Therefore, an experimental investigation was conducted to evaluate the influence of the reduction in the volume fraction and the nominal size of coarse aggregate on concrete shear strength of self-consolidating beams. Six concrete mixes were produced, four self-consolidating and two conventionally vibrated. A total of 18 beams, with flexural reinforcement but without shear reinforcement were cast. These beams were tested under a four-point loading condition. Their failure modes, cracking patterns and shear resistances were evaluated. The obtained shear resistances were compared to the theoretical values given by the ACI-318 and EC-2 codes. The results demonstrated a lower shear resistance of self-consolidating concrete beams, caused mainly due to the reduced aggregate size.

scholarly journals Effect of Recycled Coarse Aggregates in Properties of Concrete

2008 ◽  
Vol 3 (4) ◽  
pp. 130-137 ◽  
Author(s):  
R Kumutha ◽  
K Vijai
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Split Tensile Strength ◽  
Coarse Aggregates ◽  
The Cost

The properties of concrete containing coarse recycled aggregates were investigated. Laboratory trials were conducted to investigate the possibility of using recycled aggregates from the demolition wastes available locally as the replacement of natural coarse aggregates in concrete. A series of tests were carried out to determine the density, compressive strength, split tensile strength, flexural strength and modulus of elasticity of concrete with and without recycled aggregates. The water cement ratio was kept constant for all the mixes. The coarse aggregate in concrete was replaced with 0%, 20%, 40%, 60%, 80% and 100% recycled coarse aggregates. The test results indicated that the replacement of natural coarse aggregates by recycled aggregates up to 40% had little effect on the compressive strength, but higher levels of replacement reduced the compressive strength. A replacement level of 100% causes a reduction of 28% in compressive strength, 36% in split tensile strength and 50% in flexural strength. For strength characteristics, the results showed a gradual decrease in compressive strength, split tensile strength, flexural strength and modulus of elasticity as the percentage of recycled aggregate used in the specimens increased. 100% replacement of natural coarse aggregate by recycled aggregate resulted in 43% savings in the cost of coarse aggregates and 9% savings in the cost of concrete.

scholarly journals Examining Polyethylene Terephthalate (PET) as Artificial Coarse Aggregates in Concrete

2020 ◽  
Vol 6 (12) ◽  
pp. 2416-2424
Author(s):  
Erniati Bachtiar ◽  
Mustaan Mustaan ◽  
Faris Jumawan ◽  
Meldawati Artayani ◽  
Tahang Tahang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Polyethylene Terephthalate ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Coarse Aggregates ◽  
Volume Weight ◽  
Concrete Mixtures ◽  
Strength Tests ◽  
Recycled Polyethylene

This study aims to examine the effect of recycled Polyethylene Terephthalate (PET) artificial aggregate as a substitute for coarse aggregate on the compressive strength and flexural strength, and the volume weight of the concrete. PET plastic waste is recycled by heating to a boiling point of approximately 300°C. There are five variations of concrete mixtures, defined the percentage of PET artificial aggregate to the total coarse aggregate, by 0, 25, 50, 75 and 100%. Tests carried out on fresh concrete mixtures are slump, bleeding, and segregation tests. Compressive and flexural strength tests proceeded based on ASTM 39/C39M-99 and ASTM C293-79 standards at the age of 28 days. The results showed that the use of PET artificial aggregate could improve the workability of the concrete mixture. The effect of PET artificial aggregate as a substitute for coarse aggregate on the compressive and flexural strength of concrete is considered very significant. The higher the percentage of PET plastic artificial aggregate, the lower the compressive and flexural strength, and the volume weight, of the concrete. Substitution of 25, 50, 75 and 100% of PET artificial aggregate gave decreases in compressive strength of 30.06, 32.39, 41.73 and 44.06% of the compressive strength of the standard concrete (18.20 MPa), respectively. The reductions in flexural strength were by respectively 19.03, 54.50, 53.95 and 61.00% of the standard concrete's flexural strength (3.59 MPa). The reductions in volume weight of concrete were by respectively 8.45, 17.71, 25.07 and 34.60% of the weight of the standard concrete volume of 2335.4 kg/m3 Doi: 10.28991/cej-2020-03091626 Full Text: PDF

scholarly journals Influence of Reduced Water Cement Ratio on Behaviour of Concrete Having Plastic Aggregate

2018 ◽  
Vol 4 (12) ◽  
pp. 2971 ◽  
Author(s):  
Saad Tayyab ◽  
Asad Ullah ◽  
Kamal Shah ◽  
Faial Mehmood ◽  
Akhtar Gul
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Stress Strain ◽  
Cement Ratio ◽  
Coarse Aggregates ◽  
Alternative Materials ◽  
Super Plasticizer ◽  
Strain Relationship ◽  
Natural Aggregates ◽  
Reduced Water

The production and use of plastic bottles is increasing tremendously with passing time. These plastic bottles become a problem when they are disposed as they are non-biodegradable. This means that the waste plastic, when dumped, does not decompose naturally and stays in the environment affecting the ecological system. The use of alternative aggregates like Plastic Coarse Aggregate (PCA) is a natural step in solving part of reduction of natural aggregates as well as to solve the issue discussed above. The researchers are trying from half a century to investigate the alternative materials to be replaced in concrete mixture in place of either aggregate or cement.  In this research, the concrete made from plastic waste as coarse aggregates were investigated for compressive strength and Stress-strain relationship. Plastic coarse aggregate have been replaced in place of natural coarse aggregate by different percentages with w/c 0.5, 0.4 and 0.3. The percentage replacement of plastic aggregate in place of mineral coarse aggregate was 25%, 30%, 35% and 40 %. Using Super-plasticizer Chemrite 520-BAS. OPC-53 grade cement was used. Total of forty five Cylinders were prepared based on different combination of Percentage of Plastic aggregate replaced and W/C as discussed above and checked for compressive strength and stress-strain relationship. The compressive strength increases by about 19.25% due to the decrease in W/C from 0.5 to 0.3 for plastic percentage addition of 40%.

scholarly journals Sustainability of Construction Aggregates in Kuwait

2019 ◽  
Vol 2 (4) ◽  
pp. 406
Author(s):  
Sharifa Al-Fadala
Keyword(s):  
Construction Industry ◽  
United Arab Emirates ◽  
Coarse Aggregate ◽  
Waste Utilization ◽  
Recycled Aggregates ◽  
Environmental Pressures ◽  
Coarse Aggregates ◽  
Constituent Material ◽  
Construction And Demolition Wastes ◽  
Local Construction

Kuwait is facing a current construction boom with projects worth of more than USD188bn. The huge infrastructure spending plan of Kuwait is reflected with a growing demand of concrete as concrete is the most commonly used building material in the local construction. At the present, the quarrying of coarse aggregate which is a main concrete constituent material is banned in Kuwait since 1997 and construction industry depends on the imported coarse aggregates from neighbouring sources such as United Arab Emirates and Iran. Kuwait is also interested in challenging the growing concern of an effective environmental management of water, land and atmosphere to achieve a sustainable civilization. The increasingly environmental pressures coupled with the limited available economical resources are causing the decision making authorities to consider the practice of recycling and waste utilization. This paper presents Kuwait Institute for Scientific Research (KISR) efforts to investigate sustainable sources of coarse aggregate for construction industry from waste. The first sustainable source investigated is the production of synthetic lightweight aggregates utilizing combinations of argillaceous indigenous and waste materials, and the second is recycled aggregates from construction and demolition wastes. The potential of the two sustainable sources of construction aggregates are presented and the needed steps for real industrial application are addressed.

scholarly journals Experimental Study on Strength of Pervious Concrete by Using Fine Aggregate

2021 ◽  
Vol 9 (12) ◽  
pp. 895-897
Author(s):  
Atif Jawed
Keyword(s):  
Compressive Strength ◽  
Void Ratio ◽  
Rice Husk Ash ◽  
Pervious Concrete ◽  
Void Content ◽  
Fine Aggregate ◽  
Coarse Aggregates ◽  
Fine Aggregates ◽  
Flow Through ◽  
Concrete Matrix

Abstract: Pervious concrete is a special type of concrete, which consists of cement, coarse aggregates, water and if required and other cementations materials. As there are no fine aggregates used in the concrete matrix, the void content is more which allows the water to flow through its bodyThe main aim of this project was to improve the compressive strength characteristics of pervious concrete. But it can be noted that with increase in compressive strength the void ratio decreases. Hence, the improvement of strength should not affect the porosity property because it is the property which serves its purpose. In this investigation work the compressive strength of pervious concrete is increased by a maximum of 18.26% for 28 days when 8% fine aggregates were added to standard pervious concrete Keywords: W/C ratio, pervious Concrete, sugarcane bagasse’s ash, rice husk ash compressive strength, fine aggregates

Sign in / Sign up

Export Citation Format

Share Document