scholarly journals Durability of concretes prepared with crystalline admixtures

2019 ◽  
Vol 289 ◽  
pp. 09003
Author(s):  
Kosmas K. Sideris ◽  
A. Chatzopoulos ◽  
Ch. Tassos ◽  
P. Manita
Keyword(s):  
Compressive Strength ◽  
Concrete Slab ◽  
Concrete Mixtures ◽  
Durability Of Concrete

The objective of this work was to study the influence of crystalline admixtures on the durability of concrete. Four concrete mixtures – two reference concretes and two alternative mixtures-were produced during the first phase of the research. Influence of curing on the activation of the crystals was investigated on concrete slab specimens. The properties measured were the compressive strength and different durability indicators. The results revealed that crystalline admixtures enhanced the strength and the durability of the alternative mixtures.

scholarly journals The Effect of Recycled HDPE Plastic Additions on Concrete Performance

Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 18
Author(s):  
Tamrin ◽  
Juli Nurdiana
Keyword(s):  
Compressive Strength ◽  
High Density Polyethylene ◽  
Concrete Mixtures ◽  
Best Response ◽  
Structural Applications ◽  
Optimal Mix ◽  
Increased Strength ◽  
Selection Of ◽  
Recycled Hdpe ◽  
Lower Medium

This study examined HDPE (high-density polyethylene) plastic waste as an added material for concrete mixtures. The selection of HDPE was based on its increased strength, hardness, and resistance to high temperatures compared with other plastics. It focused on how HDPE plastic can be used as an additive in concrete to increase its tensile strength and compressive strength. 156 specimens were used to identify the effect of adding different percentages and sizes of HDPE lamellar particles to lower, medium, and higher strength concrete for non-structural applications. HDPE 0.5 mm thick lamellar particles with sizes of 10 × 10 mm, 5 × 20 mm, and 2.5 × 40 mm were added at 2.5%, 5%, 10%, and 20% by weight of cement. The results showed that the medium concrete class (with compressive strength equal to 10 MPa) had the best response to the addition of HDPE. The 5% HDPE addition represented the optimal mix for all concrete types, while the 5 × 20 mm size was best.

An Assessment of the Long-Term Durability of Concrete in Radioactive Waste Repositories

1985 ◽  
Vol 50 ◽  
Author(s):  
A. Atkinson ◽  
D. J. Goult ◽  
J. A. Hearne
Keyword(s):  
Reinforced Concrete ◽  
Radioactive Waste ◽  
Concrete Slab ◽  
Laboratory Studies ◽  
Preliminary Assessment ◽  
Reinforced Concrete Slab ◽  
Radioactive Waste Repositories ◽  
Waste Repositories ◽  
Durability Of Concrete

AbstractA preliminary assessment of the long-term durability of concrete in a repository sited in clay is presented. The assessment is based on recorded experience of concrete structures and both field and laboratory studies. It is also supported by results of the examination of a concrete sample which had been buried in clay for 43 years.The enoineering lifetime of a 1 m thick reinforced concrete slab, with one face in contact with clay, and the way in which pH in the repository as a whole is likely to vary with time have both been estimated from available data. The estimates indicate that engineering lifetimes of about 103 years are expected (providing that sulphate resisting cement is used) and that pH is likely to remain above 10.5 for about 106 years.

scholarly journals Relations between indirect tensile and flexural strengths for dry and plastic concretes

2013 ◽  
Vol 6 (6) ◽  
pp. 854-874 ◽  
Author(s):  
J. T. Balbo
Keyword(s):  
Tensile Strength ◽  
Concrete Slab ◽  
Plane Stress State ◽  
Concrete Mixtures ◽  
Technological Control ◽  
Strength Tests ◽  
Indirect Tensile ◽  
Actual Strength ◽  
Basic Concepts ◽  
Set Up

Indirect tensile strength is not usually used for concrete mixtures proportioning and its technological control; flexural strength tests under third point loads arrangement are the pattern for such goals. Indeed, neither of such tests have the capability to set up the actual strength of a concrete slab since its response is under plane stress state. A critical review of the basic concepts on both kinds of tests allows foreseeing its limitations as well as how to overcome such shortcomings. At last correlations between the two kinds of tensile strength are presented considering dry and plastic concretes typically applied on paving, corroborating to former results achieved for plastic concretes.

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 Utilization of copper fiber waste to increase compressive strength and split tensile strength of rigid pavement

2021 ◽  
Vol 878 (1) ◽  
pp. 012052
Author(s):  
H Ndruru ◽  
R M Simanjuntak ◽  
S P Tampubolon
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Surface Layer ◽  
Concrete Slab ◽  
Residential Areas ◽  
Split Tensile Strength ◽  
Rigid Pavement ◽  
Traffic Loads ◽  
Pavement Construction ◽  
Low Traffic

Abstract The rigid pavement is a pavement construction in which a concrete slab is used as the top layer, which is located above the foundation or directly above the subgrade, without or with an asphalt surface layer. One type of rigid pavement used in Indonesia is rigid pavement without using reinforcement which is usually used in areas with low traffic or residential areas. Pavement without using reinforcement is the small split tensile strength so that the part of the plate will experience cracks due to stresses that cannot be avoided from traffic loads. Therefore, it is necessary to have reinforcement on the concrete slab so that the cracks do not extend. In this research, the use of copper fiber waste from electronic cables as a substitute solution for reinforcement to be used as a mixture in concrete. The experiments were carried out using fiber with variations of 0%, 0.5%, 1%, and 1.5% of the total weight of concrete mixture material and then tested at 28 days of concrete age. This research showed the variation of fiber weight until 1,5% increase the split tensile strength up to 32,46% and the compressive strength up to 9,16%.

scholarly journals Mechanical Testing of Composite Steel and Reactive Powder Concrete Structural Element

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3954
Author(s):  
Jan Bujnak ◽  
Peter Michalek ◽  
Frantisek Bahleda ◽  
Stefania Grzeszczyk ◽  
Aneta Matuszek-Chmurowska ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Composite Structures ◽  
Numerical Models ◽  
Concrete Slab ◽  
Initial Study ◽  
Cementitious Materials ◽  
Mechanical Tests ◽  
Reactive Powder Concrete ◽  
Structural Element ◽  
Reactive Powder

Reactive powder concrete (RPC), typically with higher compressive strength, is particularly attractive to structural engineers to apply them in infrastructures for enhancing their resistance under severe environments and loads. The main objective of the initial study presented in the paper was to investigate the behavior of two types of these new cementitious materials differing in the nature of microfibers. The RPC mixes were reinforced with steel and then with basalt microfibers. To evaluate the structural performance of developed unconventional materials, properties were investigated experimentally and compared with the control normal concrete mix. Mechanical tests indicated that dispersing fine fibers for making RPC, a mean compressive strength of 198.3 MPa and flexural strength 52.6 MPa or 23.2 MPa, respectively, were developed after 28 days of standard curing at ambient temperatures. In composite structures consisting of steel girders and a concrete slab, it is necessary to prevent the relative slip at the steel and concrete interface using shear connectors. The very high RPC strength enabled a material saving, weight-reduced application of precast construction, and particularly effective joint to steel beams. The investigation of such shear connection efficiency, in the case of the higher strength concrete deck, using standard push-out test specimens was executed. Finite element numerical models were developed. The outputs of the studies are presented in the paper.

Compressive Strength of Concrete from Lightweight Bubbles Aggregate

2015 ◽  
Vol 754-755 ◽  
pp. 348-353 ◽  
Author(s):  
Norlia Mohamad Ibrahim ◽  
Leong Qi Wen ◽  
Mustaqqim Abdul Rahim ◽  
Khairul Nizar Ismail ◽  
Roshazita Che Amat ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Natural Resources ◽  
Concrete Structure ◽  
Concrete Mixture ◽  
New Materials ◽  
Concrete Mixtures ◽  
Compressive Strength Of Concrete

Compressive strength of concrete is the major mechanical properties of concrete that need to be focused on. Poor compressive strength will lead to low susceptibility of concrete structure towards designated actions. Many researches have been conducted to enhance the compressive strength of concrete by incorporating new materials in the concrete mixture. The dependencies towards natural resources can be reduced. Therefore, this paper presents the results of an experimental study concerning the incorporation of artificial lightweight bubbles aggregate (LBA) into cementations mixture in order to produce comparable compressive strength but at a lower densities. Three concrete mixtures containing various percentages of LBA, (10% - 50% of LBA) and one mixture used normal aggregate (NA) were prepared and characterized. The compressive strength of LBA in concrete was identified to be ranged between 39 MPa and 54 MPa. Meanwhile, the densities vary between 2000 kg/m3 to 2300 kg/m3.

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