scholarly journals Nano Silica and Metakaolin Effects on the Behavior of Concrete Containing Rubber Crumbs

CivilEng ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 264-274
Author(s):  
Navid Chalangaran ◽  
Alireza Farzampour ◽  
Nima Paslar
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Concrete Strength ◽  
Environmental Issues ◽  
Tensile Behavior ◽  
Concrete Mixture ◽  
Nano Silica ◽  
Negative Effects ◽  
Rubber Material ◽  
Concrete Aggregates

The excessive production of worn tires remaining from the transportation system and the lack of proper procedures to recycle or reuse these materials have caused critical environmental issues. Due to the rubber’s toughness, this material could be implemented to increase concrete toughness, and by crushing the tires concrete aggregates can be replaced proportionally with rubber crumbs and large quantities of scrapped rubber. However, this substitution decreases the concrete strength. In this study, crushed rubber with sizes from 1 to 3 mm and 3 to 6 mm were replaced by 5%, 10%, and 15% sand; the combination of two additives of nano silica and metakaolin additives with optimum values was used to compensate the degradation of the strength and improve the workability of the concrete. Moreover, the compressive strength, tensile behavior, and modulus of elasticity were measured and compared. The results indicate that the optimum use of nano silica and metakaolin additives could compensate the negative effects of the rubber material implementation in the concrete mixture while improving the overall workability and flowability of the concrete mixture.

scholarly journals Research on the Effect of Cooper Slag as a Fine Aggregate on the Properties of Concrete

2019 ◽  
Vol 8 (2S3) ◽  
pp. 619-623
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Copper Slag ◽  
Splitting Tensile Strength ◽  
Copper Recovery ◽  
Concrete Mixture ◽  
Copper Smelting ◽  
Fine Aggregate

Copper slag is a rough blasting grit or a by-product acquired by the process of copper smelting and refining. These copper slags are recycled for copper recovery. In this paper, we analysed copper slag’s feasibility and evaluate its total competence in M25 grade concrete. In this observation, a concrete mixture is applied with copper slag as a fine aggregate ranging from 0%, 20%, 40%, 60%, 80%, and 100% respectively. The strength of copper slag’s implementation is accomplished on the basis of concrete’s flexural strength, compressive strength and splitting tensile strength. From the obtained results, in concrete 40% percentage of copper slag is used as sand replacement. On 28 days, the modulus of elasticity increased up to 32%, the compressive strength increased up to 34% and flexural strength is increased to 6.2%. From this experiment, it is proved technically that replacing sand using copper slag as a fine mixture in M25 grade concrete.

scholarly journals PENGGUNAAN TERAK NIKEL SEBAGAI AGREGAT DALAM CAMPURAN BETON

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Wayan Mustika ◽  
I M. Alit K. Salain ◽  
I K. Sudarsana
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Coarse Aggregate ◽  
Nickel Content ◽  
Combustion Process ◽  
Weight Ratio ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Physical Form ◽  
Tensile Strenght

Nickel slag is one kind of nickel ore smelting waste after the combustion process. Production of nickel slag PT. Antam Pomalaa Kolaka Southeast Sulawesi province during the period 2011-2012 period approximately 1 million tons of slag / year, with a nickel content in ore processing of nickel is between 1.80% to 2.00%. Visually, the physical form of this nickel slag aggregate resembles. Research on the use of nickel slag as an aggregate in concrete mixture is carried out using a cylindrical specimen with a diameter of 15 cm and 30 cm high by 48 pieces were tested at 28 days with some variations in the mix. Variation 01, 100% natural aggregate, variation 02, nickel slag as coarse aggregate, variation 03, nickel slag as fine aggregate, and variation 04, nickel slag as coarse aggregate and fine aggregate. Aggregate gradation in the mixture is set and is designed so that it meets the specifications gradation mix for maximum aggregate size of 40 mm. The composition of the concrete mixture used is a mixture of concrete with the ratio of cement : fine aggegate : coarse aggregate is 1: 2: 3 in a weight ratio with cement water ratio (fas) is set at 0.5. The results showed that when compared with the use of natural agregate, terak nickel is used only as a coarse agregate, a fine agregate only and combined agregate coarse and fine agregates resulting slump values ??fell 39.47%, an increase of 55.26%, and an increase of 34.21%. As a coarse agregate, terak nickel increases the compressive strength, modulus of elasticity and splitting tensile strenght, respectively for 42.27%, 19.37% and 23.46%. As fine agregate, nickel terak resulting value of compressive strength, modulus of elasticity and tensile strength divided down respectively by 16.75%, 6.70% and 24.58%. As a combination of coarse and fine agregate, terak nickel increases the compressive strength, modulus of elasticity and splitting tensile strenght, respectively for 10.31%, 9.26% and 6.70%.  

Utilization of kimberlite tailings as aggregates in concrete – strength and selected durability properties

MRS Advances ◽  
2020 ◽  
Vol 5 (25) ◽  
pp. 1259-1266
Author(s):  
Mike Otieno ◽  
Esina Ndoro
Keyword(s):  
Compressive Strength ◽  
Water Demand ◽  
Concrete Strength ◽  
High Water ◽  
Negative Effects ◽  
Coarse Aggregates ◽  
Durability Properties ◽  
Mix Proportioning ◽  
Water Sorptivity ◽  
Strength And Durability

AbstractThe feasibility of using kimberlite tailings as aggregates in concrete was assessed. Compressive strength and selected durability tests were carried out on concretes made using various replacement levels (0, 40, 60 and 100%) fine and/or coarse blended crushed andesite and kimberlite tailings as aggregates. A w/b ratio of 0.50 and a CEM I 52.5R were used. The results show that the kimberlite tailings as aggregates have a relatively high water demand which was manifested as a reduction in workability of the fresh concretes with kimberlite tailings as a proportion of either fine and/or coarse aggregates. The results also showed that the use of the kimberlite tailings as a proportion of either fine or coarse aggregates in concrete resulted in a decrease in both compressive strength and durability properties viz water sorptivity and oxygen permeability. This was partly attributed to the low workability of the concretes which is known to limit the degree of compaction of fresh concrete. It is envisaged that careful concrete mix proportioning including the use of admixtures and pre-wetting of the aggregates can be used to offset the negative effects of high water demand of the kimberlite aggregates.

scholarly journals Natural aggregate totally replacement by mechanically treated concrete waste

2015 ◽  
Vol 10 (1) ◽  
pp. 83-90
Author(s):  
Jozef Junak ◽  
Nadezda Stevulova
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Reference Sample ◽  
Average Density ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Natural Aggregates ◽  
Recycled Material

Abstract This paper presents the results obtained from the research focused on the utilization of crushed concrete waste aggregates as a partial or full replacement of 4/8 and 8/16 mm natural aggregates fraction in concrete strength class C 16/20. Main concrete characteristics such as workability, density and compressive strength were studied. Compressive strength testing intervals for samples with recycled concrete aggregates were 2, 7, 14 and 28 days. The amount of water in the mixtures was indicative. For mixture resulting consistency required slump grade S3 was followed. Average density of all samples is in the range of 2250 kg/m3 to 2350 kg/m3. The highest compressive strength after 28 days of curing, 34.68 MPa, reached sample, which contained 100% of recycled material in 4/8 mm fraction and 60% of recycled aggregates in 8/16 mm fraction. This achieved value was only slightly different from the compressive strength 34.41 MPa of the reference sample.

scholarly journals Effects of Slag Addition and Mechanical Pre-Processing on the Properties of Recycled Concrete in Terms of Compressive Strength and Workability

2021 ◽  
Vol 64 (1) ◽  
pp. 11-29
Author(s):  
Madumita Sadagopan ◽  
Katarina Malaga ◽  
Magnus Lundin ◽  
Agnes Nagy
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Reference Value ◽  
Recycled Concrete ◽  
Quality Improvements ◽  
Concrete Compressive Strength ◽  
Concrete Aggregates ◽  
Crushed Concrete ◽  
Fine Aggregates ◽  
Furnace Slag

Abstract Concrete waste as crushed concrete aggregates (CCA) in structural concrete prolongs the technical life of the reference concrete accomplishing closed loop recycling. CCA concrete reaches the reference concrete compressive strength and workability by the densification of CCA and cement paste. Our previous study demonstrates CCA densification by mechanical pre-processing, aggregate quality improvements discerned by increased packing density giving reference concrete strength and workability. This study addresses paste densification with blast furnace slag (GGBS) to replace 30 (wt.%) of Portland cement at reference concrete w/b ratio 0.5 and a lower w/b 0.42. Two CCA replacements are investigated: fine aggregates, CCA50; overall aggregate replacement, CCA100. Compressive strength results show that both CCA50, CCA100 mixes achieve reference values at w/b 0.42, only CCA100 achieves reference value at w/b 0.5 as a climate-optimized concrete. The CCA50 mix-w/b 0.5 reaches reference strength when paste densification by GGBS is combined with CCA densification from mechanical pre-processing of aggregates. The 7-day strength of CCA100 with GGBS increases by 11% by mixing with pre-soaked GGBS. Statistical analysis of CCA100 strength results shows significant improvements with GGBS compared to mechanical pre-processing. Significant improvements are possible in CCA50 mix for a combination of mechanical pre-processed aggregates and GGBS replacement.

Application of Polyethylene Terephthalate Concrete as Paver Block

2019 ◽  
Vol 16 (12) ◽  
pp. 4960-4964
Author(s):  
Nor Farah Atiqah Ahmad ◽  
Siti Nooraiin Mohd Razali ◽  
Suhaila Sahat ◽  
Masiri Kaamin
Keyword(s):  
Compressive Strength ◽  
Polyethylene Terephthalate ◽  
Standard Method ◽  
Environmental Problem ◽  
Concrete Strength ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
British Standard ◽  
Pet Bottles ◽  
Single Use

This research is carried out to investigate the performance of concrete containing Polyethylene Terephthalate (PET) bottle waste as fine aggregate. PET bottle waste was chosen because it is being thrown after single use and cause environmental problem. This PET concrete then will be applied as a paver block for pedestrian walk. To reduce waste PET, the PET bottles was recycled and used in concrete mixture as a fine aggregate. PET bottles was cleaned and grinded into small irregular shape. Then, it was incorporate with the concrete and the test was conducted to find out the suitable strength for PET concrete that will be applied as paver block. The study was conducted by using cube mould to investigate the strength of the concrete. A total of four batches of concrete were produced namely, standard concrete and concrete containing PET of 5%, 10% and 15%. In this research, the compressive strength of the concrete were measured following British Standard method. The results revealed that the presence of PET in concrete will decrease the concrete performance. Nevertheless, the content of PET was specified in a specific limit to avoid the effect of concrete strength.

scholarly journals Effect of Different Types of Recycled Concrete Aggregates on Equivalent Concrete Strength and Drying Shrinkage Properties

2018 ◽  
Vol 8 (11) ◽  
pp. 2190 ◽  
Author(s):  
Sungchul Yang
Keyword(s):  
Compressive Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Concrete Strength ◽  
Drying Shrinkage ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Test Results ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates

Residual mortar attached to recycled concrete aggregate (RCA) always leads to a decrease in Young’s modulus and an increase in the drying shrinkage of RCA concrete, mainly due to an increase of total mortar volume. To overcome this inherent problem, the modified and equivalent mortar volume (EMV) methods were proposed by researchers. Despite the comparable test results, both models are still subject to the slump loss problem. Thus, under the same W/C (water to cement ratio) ratio and slump condition, this study assessed the influence of the modified EMV mix method on RCA concrete properties. A total of six mixes were proportioned using the modified EMV method with three different RCAs. Test results show that the concrete mixed with RCA produced from old PC concrete sleepers exhibited compressive strength, Young’s modulus, and flexural strength values within 2% variation, equivalent to those values of the companion natural aggregate concrete. In other mixes, compressive strength was found to decrease to 11–20%. It was observed that for 100% replacement of RCA mix, Young’s modulus increased to 10% and drying shrinkage increased to 8% only, while for 50% replacement of RCA mix, Young’s modulus decreased to 8% and drying shrinkage dropped to 4%.

The Modulus of Elasticity of High-Strength Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 233-237 ◽  
Author(s):  
Zhao Hui Lu ◽  
Zhi Wu Yu ◽  
Yan Gang Zhao
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Empirical Model ◽  
Modulus Of Elasticity ◽  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Plain Concrete ◽  
Strength Concrete ◽  
Wide Range

The paper discusses the modulus of elasticity of plain concrete for a wide range of compressive strength. A large volume of selected experimental data has been collected from existing literature and then analyzed. Particular emphasis has been given to studying the effects of concrete compressive strength and the type of coarse aggregate on the modulus of elasticity of plain concrete. The adequacy and applicability of the existing models for predicting the modulus of elasticity of high-strength concrete has been critically examined, and a new empirical model is proposed to cover concrete strength up to 125 MPa. The new empirical model seems to perform much better when applied to the published experimental data on normal weight concrete over a wide strength range.

Evaluation of the Modulus of Elasticity of Different Types of Concrete Compared with Eurocode 2

2016 ◽  
Vol 677 ◽  
pp. 181-185
Author(s):  
Klára Křížová ◽  
Rudolf Hela
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Strength Class ◽  
Raw Materials ◽  
Concrete Strength ◽  
Experimental Part ◽  
Static Modulus ◽  
Eurocode 2 ◽  
Different Types ◽  
Static Modulus Of Elasticity

The comparison of really measured compressive strength static modulus of elasticity with table values stated in Eurocode 2 is essential part of the paper. Since the standard draws from modulus of elasticity - concrete strength class, the set compressive strengths will be classified in concrete particular classes. Experimental part was based on several concrete design compositions differing in particular input raw-materials. Monitored values were set with concretes in different ages with final value 180 days. The experiment tries to demonstrate the impossibility of static modulus of elasticity derivation from table values which do not match the present-date produced concretes.

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