Influence of Maximum Aggregate Size on Compressive Strength of Concrete Exposed to Evaporation Immediately After Casting

1973 ◽  
Vol 70 (8) ◽  
Keyword(s):  
Compressive Strength ◽  
Aggregate Size ◽  
Maximum Aggregate Size ◽  
Compressive Strength Of Concrete

scholarly journals Strength Conversion Factors for Concrete Based On Specimen Geometry, Aggregate Size and Direction of Loading

2019 ◽  
Vol 8 (2) ◽  
pp. 2125-2130
Keyword(s):  
Compressive Strength ◽  
Aggregate Size ◽  
Concrete Specimen ◽  
Specimen Size ◽  
Shape Effect ◽  
Conversion Factors ◽  
Loading Direction ◽  
Compressive Strength Of Concrete ◽  
The Relationship ◽  
Specimen Shape

The main goal of this study is to find out the effect of effect of specimen shape and size, aggregate size and directions of loading and placement on the compressive strength of M20, M40, M60 and M80 grades of concrete. During the experimental study, different shaped and sized concrete specimens of different concrete mix designs were tested for compressive strength at 28 days. For casting the concrete samples, totally four different moulds were utilized, which were two different sizes of cubes and two different sizes of cylinders. The cubic moulds were 100 and 150 mm. The cylindrical moulds were 150×300 and 100×200 mm. So the relationship between size and shape effect on compressive strength of concrete samples is evaluated. Casted cubes and cylinders are tested for the compressive strength under axial compression on completion of 28 days as per IS: 516-1999.In this study, the effect of specimen sizes, specimen shapes, and placement directions on concrete compressive strengths for various grades widely used is evaluated. In addition, correlations between compressive strengths with size, shape, and placement direction of the specimen are investigated. It was found that with the increase of the size of the concrete specimen, compressive strength tends to decrease. The effect of grade of concrete on the shape effectof the compressive strength decreases as the specimen size increases regardless of strength level. Conversion factors of 0.80 to 0.90 were suggested for converting compressive strength of cylinders to compressive strength of cubes. For cubes, when the placement direction is parallel to the loading direction, the compressive strength is higher than the normal case. As aggregate size increases, compressive strength is found to be increasing.

Dynamic Compressive Strength of Cementitious Materials

1985 ◽  
Vol 64 ◽  
Author(s):  
L. E. Malvern ◽  
T. Tang ◽  
D. A. Jenkins ◽  
J. C. Gong
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Maximum Stress ◽  
Dynamic Range ◽  
Structural Response ◽  
Aggregate Size ◽  
Cementitious Materials ◽  
Rate Dependence ◽  
Maximum Aggregate Size ◽  
Inertia Effects

ABSTRACTFinite-element codes for structural response of reinforced concrete use as a parameter the unconfined compressive strength of the concrete, fc', which is sometimes increased by an arbitrary factor for dynamic loading. The objective of this research is to determine the rate dependence of fc' and eventually to model the rate-dependent constitutive behavior. Results of tests with a small Kolsky bar system and of a newly built larger system on concrete with a maximum aggregate size 1/2 inch are reported with strain rates at the maximum stress from 50 to 800/sec for mortar and from 5 to 120/sec for concrete. An apparent rate dependence up to almost twice the static strength is observed for both. The mortar shows an apparent linear dependence, while the high-strength concrete shows an approximately logarithmic dependence on the strain rate at the maximum stress, over the dynamic range observed. Some questions about specimen size effects and about how much of the apparent strain-rate effect is really a lateral inertia confinement effect are as yet unresolved. Continuing research is focused on observation of the lateral motion to assess lateral inertia effects in unconfined specimens and on passive confinement by steel jackets. Future efforts will be directed toward constitutive modeling.

scholarly journals Development of Soil Distribution and Liquefaction Potential Maps for Downtown Area in Yangon, Myanmar

2018 ◽  
Vol 4 (4) ◽  
pp. 836 ◽  
Author(s):  
Olumide Moses Ogundipe ◽  
Akinkurolere Olufunke Olanike ◽  
Emeka Segun Nnochiri ◽  
Patrick Olu Ale
Keyword(s):  
Compressive Strength ◽  
Aggregate Size ◽  
Strength Test ◽  
Strength Development ◽  
Liquefaction Potential ◽  
Downtown Area ◽  
Compressive Strength Test ◽  
Compressive Strength Of Concrete ◽  
The Right ◽  
Soil Distribution

This study investigates the effect of aggregate size on the compressive strength of concrete. Two nominal mixes, that is, 1:2:4 and 1:3:6 were used in the study. Concrete cubes were produced with 6, 10, 12.5, 20 and 25 mm aggregates for the two nominal mixes and they were subjected to compressive strength test after curing for 7, 21, 28 and 56 days. It was found in the study that the strength development follows the same trend for both nominal mixes. Also, the results show that the compressive strength increases with increasing aggregate size up to 12.5 mm, while the concrete produced using 20 mm had greater compressive strength than those produced using 25 mm aggregate. This established the importance of ensuring that the right aggregate size is used in the production of concrete. Therefore, it is recommended that careful attention must be paid to the sizes of aggregates used in the production of concrete for structural purposes.

scholarly journals Strength optimization of reactive powder concrete

2020 ◽  
Vol 13 (5) ◽  
Author(s):  
Abrahão Bernardo Rohden ◽  
Ana Paula Kirchheim ◽  
Denise Dal Molin
Keyword(s):  
Compressive Strength ◽  
Aggregate Size ◽  
Reactive Powder Concrete ◽  
Maximum Aggregate Size ◽  
Second Phase ◽  
Fine Aggregate ◽  
Inorganic Pigments ◽  
Concrete Mix Design ◽  
Fine Quartz ◽  
Reactive Powder

abstract: Recent reports on reactive powder concrete address important aspects regarding its performance. Several techniques are used to improve the design of such concretes. Ultra-high compressive strengths have been reported with the application of pre-setting pressure and autoclave curing. The objective of this work is to evaluate the use of very fine quartz powder to replace fine aggregate, nanosilica, and inorganic pigments to optimize mechanical properties of reactive powder concrete. The experimental work was developed in three distinct phases. In the first phase, mix-proportions of reactive powder concrete have been developed, considering different maximum aggregate sizes (1.2, 0.6, 0.075, and 0.045 mm). In the second phase, the influence of nanosilica on the properties of reactive powder concrete was evaluated. In the third phase, the effect of the addition of yellow, green, orange, and blue inorganic pigments to the reactive powder concrete mix-design was evaluated. Results show that the maximum aggregate size influences the compressive strength of the reactive powder concrete. A decrease from 1.2 mm to 0.045 mm in the maximum aggregate size resulted in 156 MPa increase in the compressive strength. The type of pigment did not significantly influence the compressive strength of the reactive powder concrete. The mix-proportion that resulted in the highest compressive strength (310.7 MPa) was designed using yellow pigment.

scholarly journals Analysis of Petro-Physico-Mechanical Properties of Coarse Aggregate and Its Implications on the Performance Characteristics of Concrete

2020 ◽  
pp. 45-60
Author(s):  
Larry Pax Chegbeleh ◽  
Lawrence Opanin Nkansah ◽  
Frank Siaw Ackah ◽  
Richard Adams Mejida
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Performance Characteristics ◽  
Rock Samples ◽  
Rock Types ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
The Impact

The importance of concrete as one of the major materials in the building and construction industry cannot be over emphasized due to the myriad benefits and versatility to humankind. However, its performance characteristics on the stability of engineered structures have mostly been overlooked. In this paper, petrographic characteristics and physico-mechanical properties of ten (n=10) rock samples and some quantity of coarse aggregate representing one set of samples, each obtained from two quarry sites around Amasaman and Shai Hills in the Greater Accra Region of Ghana, have been investigated. This study aimed to determine the impact of aggregate size, content and type on the compressive strength of concrete. The study was conducted through petrographic and physico-mechanical properties analyses on the samples obtained. Petrographic studies were performed on the ten (n=10) rock samples from each quarry site, while the physico-mechanical property tests were conducted directly on the coarse aggregate. However, compressive strength tests were performed on cast concretes produced from aggregates with varying sizes and type obtained from the two quarry sites. Results of the petrographic analysis reveal two rock types: Quartzo-feldspathic gneiss and Granodiorites from Amasaman quarry and also two rock types: Gneiss and Meta-granite from Shai Hills quarry. Results of the physico-mechical properties tests are consistent with requirement of approved construction standards. Compressive strength tests show increasing compressive strength of concretes with increasing aggregate nominal sizes of classes A, B and C but show reduced compressive strength for aggregate nominal sizes of class D. It can therefore, be inferred that, aggregate size and content have profound impact on compressive strength of concrete. Also, aggregate type has influence on compressive strength of concrete, as observed in higher compressive strength of concretes produced from the quartzo-feldspathic gneiss and granodiorites than concretes produced from the gneiss and meta-granites.

Statistical Size Effects on Compressive Strength and Mechanical Behavior of Concrete

2017 ◽  
Vol 754 ◽  
pp. 317-320 ◽  
Author(s):  
Chi Cong Vu ◽  
Jérôme Weiss ◽  
Olivier Plé ◽  
David Amitrano
Keyword(s):  
Compressive Strength ◽  
Size Effects ◽  
Aggregate Size ◽  
Dissipated Energy ◽  
Compression Tests ◽  
Weakest Link ◽  
Link Theory ◽  
Long Time ◽  
Compressive Strength Of Concrete ◽  
Main Shortcoming

The size effect on strength of concrete has been studied for a long time from various approaches. In particular, the weakest-link theory remains nowadays the basic tool to interpret statistical size effects, i.e. how the probability of failure under a given stress depends on external size. The main shortcoming of Weibull’s theory is that the activation of fracture from the weakest flaw is assumed to set the final strength, i.e. possible interactions between microcracks and defects during progressive damage are implicitly neglected. The objective of this study is to determine experimentally the influence of “external” (sample) size and “internal” (microstructural) size on compressive strength of concrete. For this purpose, more than 250 uniaxial compression tests were conducted on concrete specimens with two different cylindrical sizes (110×220 mm and 160×320 mm) and prepared from three different compositions (mean aggregate size and proportion). The relationships between compressive strength, dissipated energy up to failure in one hand, and microstructural as well as specimen sizes on the other hand, were analyzed statistically. This demonstrated the failure of the weakest-link approach to describe size effects on compressive strength of concrete.

scholarly journals Eksperimental Perbandingan Kekuatan Tekan Karakteristik Beton Self Compacting Menggunakan Agregat Kasar Alami Dan Agregat Kasar Daur Ulang

2020 ◽  
Vol 19 (1) ◽  
pp. 107-120
Author(s):  
Martinus Pramanata Sapeai ◽  
Johannes Adhijoso Tjondro
Keyword(s):  
Compressive Strength ◽  
Aggregate Size ◽  
Recycled Concrete ◽  
Mix Design ◽  
Sustainable Construction ◽  
Maximum Aggregate Size ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Coarse Aggregates ◽  
High Rise

Utilization of recycled concrete waste as an alternative to natural coarse aggregates in this experiment is in accordance with the concept of sustainable construction. Concrete is the main material of structural elements most commonly used in general construction and has properties that are difficult to recycle by themselves naturally. Nowdays concrete innovation with the concept of self compacting (SCC) is widely used especially in high rise building and buildings with special specification. SCC has high flowability properties so that it can flow and compact themselves, but in SCC with normal quality still need compactor. The concept of making test specimens is in accordance with real conditions in the field, where aggregates do not go through a cleaning process. There are four different mix design with the required specified compressive strength of 20 MPa. Mix design 1A (natural coarse) and 1B (recycled coarse aggregates) has a maximum aggregate size 12.50 mm, and mix design 2A (natural coarse) and 2B (recycled coarse aggregates) has a maximum aggregate size 19.00 mm. This experimental results in specified compressive strength concrete for mix design 1A, 1B, 2A, and 2B as follows: 30.93 MPa, 26.21 MPa, 30.82 MPa and 27.60 MPa. Therefore, recycled concrete aggregates can be alternative to natural coarse aggregates and can also be made into concrete with the SCC concept.

scholarly journals Studi Mengenai Perancangan Campuran Beton Abu Terbang dengan Pendekatan Blended Sand (Hal. 88-97)

2018 ◽  
Vol 4 (4) ◽  
pp. 88
Author(s):  
Reza Fauzi Nirwan ◽  
Priyanto Saelan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Aggregate Size ◽  
Maximum Aggregate Size ◽  
Fine Aggregate ◽  
Concrete Compressive Strength ◽  
Fly Ash Concrete ◽  
Is Research ◽  
Strength Tests ◽  
Concrete Mix

ABSTRAKPenelitian ini dilakukan untuk mengetahui hasil perancangan campuran beton abu terbang yang mensubtitusi semen dengan cara pendekatan sand blended, yaitu abu terbang yang mensubtitusi semen diperlakukan sebagai agregat halus, sehingga agregat halus merupakan campuran dari pasir dan abu terbang. Penelitian dilakukan dengan kuat tekan rencana 20 MPa dan 30 MPa. Substitusi semen oleh abu terbang sebesar  10 %, 20 %, dan 30 % dari berat semen. Ukuran maksimum agregat kasar yang digunakan adalah 20 mm, dan pasir dengan modulus kehalusan 2,768, slump rencana 6 cm dan 10 cm. Hasil pengujian tekan silinder beton berdiameter 10 cm dan tinggi 20 cm menunjukkan bahwa kuat tekan beton abu terbang yang dihasilkan berdekatan dengan beton acuan yaitu beton tanpa abu terbang, untuk semua kadar abu terbang yaitu sampai dengan kadar subtitusi semen oleh abu terbang sebesar 30 %. Pendekatan sand blended dapat dilakukan dalam perancangan campuran beton abu terbang.Kata Kunci : beton abu terbang, kuat tekan, pasir blendedABSTRACTThis is research was performed to know the result of the test of fly ash concrete mix designed by sand blended method. Fly ash will be treated as fine aggregate so that the total fine aggregate is the consist of fly ash and sand. 20 MPa and 30 MPa concrete mix are designed for 10 %, 20 % and 30 % by weight of cement subtitution by fly ash. Concrete mix use 20 mm maximum aggregate size, finess modulus of sand 2.768, and 6 cm and  10 cm slump. Compressive strength tests of 10 cm diameter and 20 cm height cylinder showed that the stength of fly ash concrete is the same as the strength of initial concrete. Fly ash concrete mix can be designed by sand blended approximation.Keywords : fly ash concrete, compressive strength, blended sand

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