May 2019 1 scope this standard is 516 part 5 specifies nondestructive test methods for use on hardened concrete. Prediction of concrete carbonation depth using decision trees. Astm c876 pdf this standard is issued under the fixed designation c. Efficient, it can manage depth of carbonation testing whilst cutting financial and physical resources down to a minimum. Pdf concrete carbonation test in natural and accelerated conditions. Carbonation depth of concrete was tested by 1% phenolphthalein reagent, which was prepared by 95% ethyl alcohol. Section 3 carbonation depth test first revision ics 91. Laborato storage conditions 28 day tm 1 year carbonation depth, mm c02, i mp, i rh, i. Carbonation testing of hardened concrete and the effect of. This procedure is a method for evaluating the carbonation resistance of concrete using an accelerated carbonation test. Fundamental modeling and experimental investigation of. Concrete carbonation and chloride penetration in research.
Measuring carbonation in concrete lab testing class. The measurement ofcarbonation depth using the phenolphthalein solution wascarried out by. Explore vip membership depth of carbonation chloride content cement content sulphate content type of cement alkali content carbonation test on concrete structures this test. Pdf concrete carbonation test in natural and accelerated. Below 25 per cent relative humidity, the degree of carbonation that takes place is considered insignificant.
Slump values also had a tremendous impact on carbonation depth, increase in slump increases depth of carbonation. International atomic energy agency wagramer strasse 5 p. The strict physicochemical significance of the phenolphthalein color test for estimating depth of penetration by carbon dioxide gas is. Determination of carbonation depth in hardened concrete by the phenolphthalein method.
This section section 3 of the standard covers the procedure of determination. During the test, the broken or cored surface is sprayed with phenolphthalein solution to detect the loss of alkalinity associated with carbonation. Application assess durability of concrete by comparing carbonation depth with concrete cover. For example, if the carbonation depth is 1mm in a oneyearold concrete, it will be about 3mm after 9 years, 5mm after 25 years and 10mm after 100 years. Mar 24, 2015 carbonation of concrete carbonation of concrete is one of the reasons for corrosion of reinforcement. Articles like this one can provide a lot of useful material. Carbonation of hydrated portland cement astm international. The carbonation test is essentially a ph test indicating the depth of ph reducing effects of carbonation into the concrete member.
The test is most commonly carried out by spraying the indicator on freshly exposed surfaces of concrete broken from the structure or on split cores. Carbonation test set utest material testing equipment. Carbonation depth is assessed using a solution of phenolphthalein indicator that appears pink in contact with alkaline concrete with ph values in excess of 9 and colourless at lower levels of ph. Carbonation level reference chart the values in this table assume sealevel altitude, beer specific gravity of 1. If the depth of carbonation needs to be established, then a simple method to test this is to treat the concrete with phenolphtha lein. After the concrete carbonation test reached the preset carbonation age 28 d, the compressive strength and carbonation depth of specimens were tested subsequently. This prevents penetration of the carbon dioxide it would be difficult to have concrete carbonation in fully immersed concrete. Test specimens were exposed to accelerated carbonation test. The depth of carbonation measurement can be found by applying phenolphthalein solution to a freshly exposed concrete surface, the more alkaline concrete with a ph in the region of 9 or above showing pink, the carbonated more acidic concrete remaining clear. Pdf carbonation depth was verified in 40 points of two 57 years old concrete viaducts. Carbonation test on concrete structures this test is carried out to determine the depth of concrete affected due to combined attack of atmospheric carbon dioxide and moisture causing a reduction in level of alkalinity of concrete.
The tests most frequently carried out chemical tests on concrete structures are. Carbonation depth testing birmingham city laboratories. Carbonation depth is generally assessed on site using a solution of phenolphthalein indicator that appears pink in contact with alkaline concrete with ph values in excess of 9 and colourless at lower levels of ph. However, the water binder ratio is still a key factor affecting the carbonation depth of concrete. Consequently, the phenolphthalein solution has limitations with regards to monitoring the carbonation depth, as it is not able to detect within the range where the loss of alkalinity begins, which.
Carbonation test set, concrete testing equipment, controls. Carbonation depth is the average distance from the surface of concrete or mortar where carbon dioxide has reduced the alkalinity of the hydrated cement nordtest, 1989. Efficient, it can manage depth of carbonation testing whilst cutting. Empirical quantitative models of this type have been proposed in the past. Oxygen and moisture are the other components required for corrosion of embedded steel. A study of the cen test method for measurement of the. Tests for carbonation typically require a core to be extracted or a sample to be cut from the concrete. Carbonation in concrete and effect on steel corrosion final report, state job no. Prediction model for the carbonation of postrepair.
Cbu200418 rep566 august 2004 presented at rilem meeting, koriyama, japan, september 2004. The results obtained, the good estimate of the compressive strength cs mpa and the carbonation depth cd mm of only be deduced by determining the height of capillary initial imbibition of concretes zi mm for one hour. The students made concrete from different mixture designs and then compared their rate of carbonation in a high carbon. Carbonation of concrete is one of the main reasons for corrosion of reinforcement. Phenolphthalein is the accepted indicator for this purpose but it should be noted that the ph at which the colour changes may be lower than that at which passivity has been lost. The carbonation coefficients measured from bridge extracted cores ranged from 0 to 14 mmly, with a median value of 1. Guidebook on nondestructive testing of concrete structures. Astm c876 15 standard test method for corrosion potentials. The carbonation depth increases with the increase the relative humidity and reaches the peak when the relative humidity is in the range of 6070%.
The formula for the average carbonation depth of concrete at different ages is calculated as where is the average carbonation depth of the test blocks after t days and n is the total point numbers on two sides surface. The test is described in bre information sheet ip681, carbonation of concrete made with dense natural aggregates. Pdf carbonation depth in 57 years old concrete structures. Carbonation of concrete is a process by which carbon di oxide from the air penetrates into the concrete. Carbonation is a serious problem for many reinforced. Carbonation depth was measured by the phenolphthalein test, in 90 mm diameter drill cores extracted from the test slabs, in accordance with the rilem cpc 18 recommendations 10. After a period of preconditioning, the test is carried out under controlled exposure conditions using an increased level of carbon dioxide to which.
Cpc18 measurement of hardened concrete carbonation depth. Comparison between carbonation coefficients obtained in the the. Test set is conforming to en 295 for measurement of the depth of carbonation and including. Pdf concrete carbonation is one of the main causes of. It is analyzed either by an accelerated carbonation test or by measuring the development of the carbonation depth from an existing concrete structure. Diagnosing and repairing carbonation in concrete structures. Carbonation of concrete depletes the passivating layer surrounding the reinforcing steel by way of reduction in ph. Influence of carbonation depth on concrete strength evaluation carried out using the sonreb method. It is not suitable for concrete made with calcium aluminate cement. Carbonation depth determination carbontest, concrete. It is a process by which carbon dioxide from air penetrates into the concrete and reacts with calcium hydroxide to form calcium carbonates. Box 100 a1400 vienna, austria guidebook on nondestructive testing of concrete structures iaea, vienna, 2002 iaeatcs17. Minimal operator training and no special equipment required.
Pdf influence of carbonation depth on concrete strength. In this test phenolphthalein solution is used as indicator. The depth of carbonation can be determined by different techniques. Test specimens were exposed to accelerated carbonation test atmospheres containing 0. Also, modifications in microstructure of hardened cementitious materials due to carbonation were investigated in order to clarify the effect on chloride penetration. Carbonation of concrete carbonation of concrete is one of the reasons for corrosion of reinforcement. Effects of environmental factors on concrete carbonation depth. Concrete carbonation testing rebar repairs sussex rope. The test is covered by bs en 14630, products and systems for the protection and repair of concrete structures. Since carbonation is a slow process, it is usually investigated by performing accelerated test with a higher co.
Critical carbonation depth for initiation of steel corrosion in fully. It is often necessary to use other data such as chloride contents, depth of carbonation, delamination survey findings, rate of corrosion results, and environmental exposure. The optimum condition for rapid concrete carbonation to occur is at a humidity level of 5075%. Equipment for carbonation depth measurement test 67 5. Department of civil engineering and mechanics college of engineering and applied science. The carbonation test is very useful to make an initial.
Thanks to the simplicity of the test and the lack of the typical difficulties of traditional methods, it can be carried out on every kind of structure. A they lack a fundamental basis, these models cannot be. The method of testing consists of determining the depth of the carbonated layer on the surface of hardened concrete by means of an indicator. Numerical simulation on carbonation depth of concrete. Carbonation is dependent on the relative humidity of the concrete. The highest rates of carbonation occur when the relative humidity is maintained between 50 per cent and 75 per cent. Introduction the majority of concrete deterioration is connected to corrosion of reinforcement due to carbonation or chlorideinduced depassivation of steel bars. Jan 17, 2019 this video was made by a team of students from my concrete durability class. Carbonation and chloride of concrete development bureau. Determination of carbonation depth in hardened concrete by the phenolphthalein method toggle navigation. The carbonation test is very useful to make an initial assessment of reinforced concrete structures. Concrete carbonation test in natural and accelerated conditions article pdf available in advances in cement research 154.
This simple test allows the measurement of depth of carbonation through the surface of concrete. In most cases, a solution of phenolphthalein is applied to the freshly fractured face of the concrete sample to determine the presence and depth of carbonation. Results obtained in less than five minutes are easy to interpret. The carbonation depth is approximately proportional to the square root of time. Carbonation testing conditions of concrete were acquired by the environmental simulation test system. Repairing carbonation the building research establishments digest 444, part 3 and the concrete societys. Concrete, carbonation, surface coatings, cracking 1. Figure 5 shows the approximate relationship, predicting that if the carbonation depth. The students made concrete from different mixture designs and then compared their rate of carbonation. In this test, the depth of carbonation is determined. Introduction the majority of concrete deterioration is connected to corrosion of reinforcement due to carbonation or chlorideinduced depassivation of. This video was made by a team of students from my concrete durability class. At these times, four cores from each mix were removed from the chamber and the depth of carbonation was determined by splitting the core longitudinally and spraying the split surface with a 1% phenolphthalein indicator.
Product investigation assessment of the depth of carbonation using carbontest is carried out in a short time and at low cost. General description carbonation is a serious problem for many reinforced concrete buildings that have been in service for some decades. Carbonation and chloride penetration were also measured periodically over a sixyear period, in the case of the test slabs exposed in conditions a and b, and over a. Steel reinforcement in concrete may be at risk of corrosion if the cover is carbonated. Carbonation testing is performed by phenolphthalein staining. After a period of preconditioning, the test is carried out under controlled exposure conditions using an increased level of carbon dioxide to which, the vertical sides of the specimen are exposed.
Hence it was found that carbonation depth is directly proportional to waterbinder ratio11. Carbo detect is a simple colored dye field test for detecting carbonation. The set consists of two 250 ml washing bottles containing distilled water and phenolphthalein solution, and a ruler for depth of carbonation. General procedure for carbonation depth measurement test 67 5.
Such tests have also been used to develop equations to evaluate the carbonation depth from which the endurance life of concrete can be. Center for byproducts utilization chloride ion penetration test, carbonation depth test, and saltscaling test by tarun r. Concrete carbonation depths observed in the bridges were as high as 50 mm, with an average value of i0 mm. Save page to pdf the page to pdf system has been restored. The rate of carbonation depends on the grade of concrete, permeability of concrete, whether the concrete is protected or not, depth of cover, time, etc. With knowledge of the age of the structure, the carbonation depth can be converted to a carbonation rate, from which an estimation can be made of the increasing risk of corrosion due to carbonation in the future. Carbonation depth determination carbontest controls group. In concrete carbonation test, the depth of carbonation is also confirmed with microscopy either optical microscopy using the thin concrete section or scanning electron microscopy using polished concrete section. Depending on the concrete quality and curing condition, the carbonation depth varies. General procedure for carbonation depth measurement test. Carbonation is a serious problem for many reinforced concrete buildings. This simple test set is used for determination of carbonation depth of the carbonated layer near the surface of hardened concrete.
This fundamental characteristic of the hydration product is closely related to the elastic modulus, waterloss shrinkage, carbonation shrinkage, degree of carbonation, and water permeability of the paste. Measurement made by taking the average of 5 readings made on each face. Carbonation depth increases with increase in waterbinder ratio 10. Effects of accelerated carbonation on physical properties of mortar. What are different chemical tests on concrete structures. Carbontest kit for carbonation depth determination. Method of measuring depth of carbonation 50mm slice broken from prism and phenolphthalein sprayed on freshly broken surface. The percentage of co2 present is air vary from place to place.