Therefore, the relationship between the compressive and tensile strengths of the RCC should be analyzed. Unfortunately, only a few studies have been. In this study, the relationship between compressive and splitting tensile strength of old concrete existing for long period under marine. ABSTRACT. This experimental study is intended to identify the relationship between compressive strength and splitting tensile strength of high performance .
Cores Processing The drilled cores were carefully processed including incising and end faces dealing before mechanical tests. Cores Incising Based on the mentioned test specification [ 23 ], after processing, the height-diameter ratio of core samples should be 1 theoretically, which can value from 0.
Incision machine with double parallel blades was used and the distance between two blades will determine the height of each core. Before incising, the distance of double blades was carefully adjusted and then fixed, in order to ensure that the height-diameter ratio of each core is in the allowed range as 0. The incising procession is shown in Figure 2 a. Incision progress and the incised cores. After incision, cores were paired up. Two cores of each pair were confirmed to be obtained from close enough locations.
The matched cores were placed in pairs shown in Figure 2 b. Cores Selecting and Loading Test Preparing According to the test specification [ 23 ], there should be no more than 1 steel bar in qualified core and the diameter of steel bar should be less than 10 mm. The possibly existing steel bar should be vertical to the shaft of core.
Samples with obvious cracks or flaws were excluded.
According to the above prerequisites, 96 eligible cores 48 pairs were finally selected. The end faces of all cores were levelled. Belt grinder machine or polymer cement mortar was adopted to make end faces smooth and level, as shown in Figure 3 a. End face levelling, measuring scale, and preparing for loading tests. The scales of each qualified core sample were measured. Vernier caliper was applied to measure the diameters. Diameter was measured twice for each core at two vertical places and the average value was adopted as the final diameter, which would be applied in the further strength calculation Figure 3 b.
Steel tap was applied to measure the core height Figure 3 c. Lines were drawn on those samples that would be tensile split to indicate the failure areas, as shown in Figure 3 d. Loading Test All of the 96 core samples were numbered before loading test.
Every two cores of each pair were the same batch of concrete and deteriorated by environment equally: Two universal testing machines with measuring range as KN and KN are applied to compressive and tensile splitting test, respectively.
Relation Between Compressive and Tensile Strength of Concrete
Finally, 48 compressive strengths were obtained, as well as 48 tensile splitting strengths. Compressive and tensile splitting tests are shown in Figures 4 a and 4 b. Test information as serial number, sample scale, and the maximum applied force of each core sample is given in Table 2.
- There was a problem providing the content you requested
- Compressive strength
Data number consists of a three-part code, and the aleph A, B, C, and D represents the group of samples, which also indicates the places where concrete cores were drilled. The second figure in data number presents the sequence of sample pair in each group. The third figure in data number indicates the type of mechanical experiment: The primary data of experiment.
Strength Calculation According to the technical specification for testing concrete strength with drilled core [ 23 ], compressive strength of core sample was calculated as follows: The tensile split strength was calculated as [ 23 ] where is the measured maximum splitting force of each sample; is the area of split section; 0. Size Effect In the above technical specification [ 23 ], diameter of standard concrete core is mm.
However, there are usually large amount of steel bars in the field testing structures; as a result, drilling standard cores may cause damage to the reinforcement. Therefore, nonstandard cores with smaller scale are widely adopted in actual engineering, as well as in this study. Besides, different guidelines or codes may also adopt specimens with different shapes or sizes. Hence, this paper does not take account of the size effect on compressive strength.
The major difficulty of this research was the utilization of recycled aggregates of chalky origin. In fact, the majority of mountains of the Middle East region are calcareous, and the provided aggregates absorb much more water than siliceous or other types of gravels.
Only this restriction has been shown responsible of getting lower values of strength for ordinary and recycled concrete All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.
Advances in Materials Science and Engineering
Therefore, different tests have been done depending on the aggregates sizes, their origin, and also on the utilization of plasticizer and the addition of cement. The resulted recommendations have indicated a special composition for assessing acceptable values for concrete compression strength. The present research work consists of an experimental study assessing the impact of using recycled aggregates on the concrete tensile strength.
We are especially interested in determining the relationship between the compressive and tensile strength for the special mixture of recycled concrete which has been considered satisfactory. Old concrete obtained from the demolition of old buildings Type A: Calcareous Recycled Aggregates Sil-Cal: The tensile strengths obtained correspond to the mean value of 4 specimens having the same shape, dimensions, and age as in the case for compression but failing by the Brazilian test.
But for other percentages, the difference was significant. Also we recommended using old concrete, as Recycled Aggregates, when making the normalization tests, especially because it will be the reality after wars or natural catastrophes. Table 2 shows the compressive strength of concretes when using recycled aggregates obtained from old concrete.
The ratio is furthermore affected by the grading of aggregate. This is probably due to the different magnitude of the wall effect in beams and in compression specimens: The influence of incomplete compaction is similar to that of entrained air. Incidentally, the value of the compressive strength is also not unique but is affected by the shape of the test specimen.
So the numerical value of the ratio of the tensile strength to the compressive strength is not the same. For these reasons, in expressing the ratio of the tensile to compressive strengths, the test method must be explicitly stated. If the value of flexural strength is of interest, a factor relating the splitting strength to flexural strength needs to be applied.
Numerical Relationship It is expected that these two types of strengths are closely related, but there is no direct proportionality. It is noticed that with the increment of compressive strength, the tensile strength is also increased but at a decreasing rate. A better correlation is found between the various measures of tensile strength and the square root of the compressive strength.
The former value is used by the American Concrete Institute, but Gardner and Poon found a value near the later, cylinders being used in both cases. Probably the best fit overall is given by the expression: If the stress is expressed in pounds per square inch the co-efficient is replaced by 1. The above expression was suggested by Raphael. An expression used in British Code of practice BS