using a strength estimation equation written using the relation between ultrasonic velocity and compressive strength that was conﬁrmed in advance with specimens fabricated based on con-ditions similar to the concrete in the target structure.1 The ultrasonic velocity is known to be strongly affected by the water content of concrete. If a concrete specimen is dried, by

01/07/2006· (7) is a mathematical formulation designed to approximately describe the compressive strength of the Portland cement concrete over a certain restricted range of the variables involved. This equation provides a clear indication of the range of compressive strengths obtainable by simply varying the water to cement ratio.

This property involves using a strength estimation equation written using the relation between ultrasonic velocity and compressive strength that was confirmed in advance with specimens fabricated based on conditions similar to the concrete in the target structure. 1

Estimation of the Compressive Strength of Concrete under Point Load and its Approach to Strength Criterions Vol. 19, No. 6 / September 2015 − 1769 − compression (Bienieviski, 1974). The point-load strength is calculated as the ratio of the applied load to the square of the core diameter for core sample (diametral test) or cross sectional area

The compressive strength of concrete at an age t depends on the type of cement, tem-. perature and curing conditions. For a mean temperature of 20°C an d curing in accordance. with EN 12390 the ...

compressive strength of concrete. Seven different parameters namely 3/4 mm sand, 3/8 mm sand, cement content, gravel, maximums size of aggregate, fineness modulus, and water-cement ratio were considered as input variables. For each set of these input variables, the 28 days compressive strength of concrete were determined. A total number of 140 input-target

Compressive strength of concrete is a very important parameter in the quality control of both new and existing concrete pavement. It has been widely used to evaluate the concrete strength both in the laboratory and in the construction field regardless of whether numerous mix designs or identical mixtures are used. Errors usually happen in the compressive strength test even if the mixture is ...

Study on estimation for compressive strength of concrete by ultrasonic method October 2015 Journal of Structural and Construction Engineering (Transactions of AIJ) 80(715):1375-1383

Giving maximum value of compressive strength (f max) = f m +2s. And minimum probable value of compressive strength (f min)=f m-2s, if only 95.4 percent of middle area of graph is only significantly considered. Similarly, If only 68.2 percent of graph is significantly considered then, Maximum probable value of compressive strength (f max) = f m +s

An equation and correlation curves are presented for the locally used materials and mixes relating the strength of types 1, 2, and K cement concretes obtained in the accelerated-curing metheds and the 28- day strengthobtained with standard-curing conditions. Based on the results from this investigation and those of other investigators from various parts of the world, an equation applicable ...

The compressive strength of concrete at an age t depends on the type of cement, tem-. perature and curing conditions. For a mean temperature of 20°C an d curing in accordance. with EN 12390 the ...

Compressive strength of concrete is a very important parameter in the quality control of both new and existing concrete pavement. It has been widely used to evaluate the concrete strength both in the laboratory and in the construction field regardless of whether numerous mix designs or identical mixtures are used. Errors usually happen in the compressive strength test even if the mixture is evenly mixed …

Age Strength 1 day 16% 3 days 40% 7 days 65% 14 days 90% 28 days 99% Compressive strength of different grades of concrete at 7 and 28 days Grade of Min. compressive Specified characteristic Concrete strength compressive strength N/mm2 at 7 days (N/mm2) at 28 days G15 10 15 G20 13.5 20 G25 17 25 G30 20 30 G35 23.5 35 G40 27 40 M45 30 45

compressive strength of concrete. Seven different parameters namely 3/4 mm sand, 3/8 mm sand, cement content, gravel, maximums size of aggregate, fineness modulus, and water-cement ratio were considered as input variables. For each set of these input variables, the 28 days compressive strength of concrete were determined. A total number of 140 input-target

01/02/2001· He hypothesized that age and temperature above a datum temperature had the equal effects on the strength development of concrete and expressed the maturity as the following equation: (1) M= ∑ 0 t (T c −T 0 c)Δt where M is the maturity at age t, T c is the average temperature of concrete during time interval Δt (°C), and T 0 c is the datum temperature (°C). The datum temperature is the lowest temperature at which the strength …

equation for the prediction of concrete compressive strength at different ages (e.g. 7 and 28 days). The variables used in the prediction models were from the knowledge of the mix itself, i.e. mix proportion elements (cement, water, sand, aggregate and density). The proposed model proved to be a major tool in predicting compressive strength of different concretes from a ready mix (RMX) plant ...

Study on estimation for compressive strength of concrete by ultrasonic method October 2015 Journal of Structural and Construction Engineering (Transactions of AIJ) 80(715):1375-1383

This study demonstrated that the neural network techniques are effective in estimating the compressive strength of concrete based on the mix proportions. Application of these techniques will ...

The producer shall provide the user the compressive strength class of the concrete and, if ... Also another empirical equation is that deduced by Bolomey [31,45-47]: fc = p1 (W/C 1 - p2) (4.2.3) where p1 is a strength factor depending on cement type, aggregate type and air content (MPa) and p2 a time factor depending mainly on time, type of curing, and early strength class (cement fineness ...

Compressive strength of concrete has been predicted using evolutionary artificial neural networks (EANNs) as a combination of artificial neural network (ANN) and evolutionary search procedures, such as genetic algorithms (GA). In this paper for purpose of constructing models samples of cylindrical concrete parts with different characteristics have been used with 173 experimental data patterns.

Age Strength 1 day 16% 3 days 40% 7 days 65% 14 days 90% 28 days 99% Compressive strength of different grades of concrete at 7 and 28 days Grade of Min. compressive Specified characteristic Concrete strength compressive strength N/mm2 at 7 days (N/mm2) at 28 days G15 10 15 G20 13.5 20 G25 17 25 G30 20 30 G35 23.5 35 G40 27 40 M45 30 45

The point load strength (I s (50)) is an alternative mechanical parameter to predict the compressive strength of concrete. The scope of this investigation is to develop an empirical equation relating the point load strength and compressive strength of concrete.

Compressive strength of concrete is a very important parameter in the quality control of both new and existing concrete pavement. It has been widely used to evaluate the concrete strength both in the laboratory and in the construction field regardless of whether numerous mix designs or identical mixtures are used. Errors usually happen in the compressive strength test even if the mixture is evenly mixed …

equation for the prediction of concrete compressive strength at different ages (e.g. 7 and 28 days). The variables used in the prediction models were from the knowledge of the mix itself, i.e. mix proportion elements (cement, water, sand, aggregate and density). The proposed model proved to be a major tool in predicting compressive strength of different concretes from a ready mix (RMX) plant ...

The producer shall provide the user the compressive strength class of the concrete and, if ... Also another empirical equation is that deduced by Bolomey [31,45-47]: fc = p1 (W/C 1 - p2) (4.2.3) where p1 is a strength factor depending on cement type, aggregate type and air content (MPa) and p2 a time factor depending mainly on time, type of curing, and early strength class (cement fineness ...

Compressive strength of concrete has been predicted using evolutionary artificial neural networks (EANNs) as a combination of artificial neural network (ANN) and evolutionary search procedures, such as genetic algorithms (GA). In this paper for purpose of constructing models samples of cylindrical concrete parts with different characteristics have been used with 173 experimental data patterns.

respectively, for the estimation of the compressive strength of concrete elements requires some correlations which can be determined based on the statistical regression of the experimental data and should be calibrated through compressive tests carried out on cores or laboratory prepared specimens (Concu et al., 2016).

This equation has been used successfully to predict the compressive strength for ordinary Portland cement also ... Earlier and accurate estimation of concrete strength are valuable to the construction industry. The presence of such model would possibly obtain the hard balance and equality between controlling the quality (quality control process) and economics (saving time and expense, i.e ...

ASTMC1074, the standard practice for maturity, defines the method as “a technique for estimating concrete strength that is based on the assumption that samples of a given concrete mixture attain equal strengths if they attain equal values of the maturity index.”

The concrete compressive strength of an existing concrete structure is typically measured by the Schmidt hammer test , a nondestructive testing method. Rebound hardness measured by the Schmidt hammer test is influenced by the environmental condition surrounding the concrete, and it is known to be about 20% lower in an environment where the surface is moist than where it is dry [ 23 ].