scholarly journals Optimizing a Test Method to Evaluate Resistance of Pervious Concrete to Cycles of Freezing and Thawing in the Presence of Different Deicing Salts

2021 ◽  
Author(s):  
Chehong Tsang ◽  
Medhat H. Shehata ◽  
Abdurrahmaan Lotfy
Keyword(s):  
Potassium Acetate ◽  
Standard Test ◽  
Test Method ◽  
Pervious Concrete ◽  
Cycle Duration ◽  
Freezing And Thawing ◽  
Deicing Salts ◽  
Temperature Ranges ◽  
Calcium Magnesium

The lack of a standard test method for evaluating the resistance of pervious concrete to cycles of freezing and thawing in the presence of deicing salts is the motive behind this study. Different sample size and geometry, cycle duration, and level of submersion in brine solutions were investigated to achieve an optimized test method. The optimized test method was able to produce different levels of damage when different types of deicing salts were used. The optimized duration of one cycle was found to be 24 h with twelve hours of freezing at −18 °C and twelve hours of thawing at +21 °C, with the bottom 10 mm of the sample submerged in the brine solution. Cylinder samples with a diameter of 100 mm and height of 150 mm were used and found to produce similar results to 150 mm-cubes. Based on the obtained results a mass loss of 3%–5% is proposed as a failure criterion of cylindrical samples. For the materials and within the cycles of freezing/thawing investigated here, the deicers that caused the most damage were NaCl, CaCl2 and urea, followed by MgCl2, potassium acetate, sodium acetate and calcium-magnesium acetate. More testing is needed to validate the effects of different deicers under long term exposures and different temperature ranges.

Durability of concrete containing chloride-based accelerating admixtures

1990 ◽  
Vol 17 (1) ◽  
pp. 102-112
Author(s):  
T. Rezansoff ◽  
D. Stott
Keyword(s):  
Calcium Chloride ◽  
Dynamic Modulus ◽  
Linseed Oil ◽  
Standard Test ◽  
Test Method ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Cement Ratio ◽  
Freeze Thaw ◽  
Water To Cement Ratio

The influence of CaCl2 or a chloride-based accelerating admixture on the freeze–thaw resistance of concrete was evaluated. Three air entrained mix designs were investigated using ASTM C666-84, Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing. All mix designs were similar, using cement contents of 340–357 kg/m3 of concrete, except for the addition of either 2% calcium chloride or 2% High Early Pozzolith, while no accelerating admixture was added to the control mix. The entire test program was repeated four times with water-to-cement ratio of 0.46 and three times with the ratio of 0.43. For the Pozzolith-accelerated concrete, half the samples were coated with boiled linseed oil in all seven series. For the control (unaccelerated) concrete, half the samples were coated with boiled linseed oil in one series for each water-to-cement ratio. Performance was monitored using the dynamic modulus of elasticity as obtained from transverse resonant frequency measurements. Weight loss of the specimens was also measured. Only the control samples (no accelerators) showed sufficient durability to satisfy the standard of maintaining at least 60% of the original dynamic modulus after 300 cycles of alternate freezing and thawing. Sealing with linseed oil showed inconsistent improvement in the durability in the various test series when defined in terms of the dynamic modulus; however, weight losses were the lowest of all categories and surface scaling was minimal. Key words: concrete, durability, freeze–thaw testing, calcium chloride, admixtures, sealants, air void system.

scholarly journals Long-Term Field Performance of Pervious Concrete Pavement

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Aleksandra Radlińska ◽  
Andrea Welker ◽  
Kathryn Greising ◽  
Blake Campbell ◽  
David Littlewood
Keyword(s):  
Field Performance ◽  
Concrete Pavement ◽  
Pervious Concrete ◽  
Unit Weight ◽  
Freezing And Thawing ◽  
Porous Pavement ◽  
Pavement Thickness ◽  
Multiple Samples ◽  
Term Field

The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and the depth and degree of clogging. It was concluded that improper placement and curing led to uneven pavement thickness, irregular pore distribution within the pervious concrete, and highly variable strength values across the site, as well as sealed surfaces that prevented infiltration.

scholarly journals Macro Photography as an Alternative to the Stereoscopic Microscope in the Standard Test Method for Microscopical Characterisation of the air-void System in Hardened Concrete: Equipment and Methodology

2018 ◽  
Author(s):  
Fernando Suárez ◽  
José J. Conchillo ◽  
Jaime C. Gálvez ◽  
María J. Casati
Keyword(s):  
Standard Test ◽  
Test Method ◽  
Hardened Concrete ◽  
Large Set ◽  
Alternative Procedure ◽  
Freezing And Thawing ◽  
Point Count ◽  
Void System ◽  
Freezing And Thawing Cycles ◽  
Air Void

The determination of the parameters that characterise the air-void system in hardened concrete elements becomes crucial for structures under freezing and thawing cycles. The ASTM C457 standard describes some procedures to accomplish this task, but they are not easy to apply, require specialised equipment such as a stereoscopic microscope and result in highly tedious tasks to be performed. This paper describes an alternative procedure to the modified point-count method described in the Standard that makes use of macro photography. This alternative procedure is successfully applied to a large set of samples and presents some advantages over the traditional method, since the required equipment is less expensive and provides a more comfortable and less tedious procedure for the operator.

scholarly journals Macro Photography as an Alternative to the Stereoscopic Microscope in the Standard Test Method for Microscopical Characterisation of the Air-Void System in Hardened Concrete: Equipment and Methodology

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1515
Author(s):  
Fernando Suárez ◽  
José Conchillo ◽  
Jaime Gálvez ◽  
María Casati
Keyword(s):  
Standard Test ◽  
Test Method ◽  
Hardened Concrete ◽  
Large Set ◽  
Alternative Procedure ◽  
Freezing And Thawing ◽  
Point Count ◽  
Void System ◽  
Freezing And Thawing Cycles ◽  
Air Void

The determination of the parameters that characterize the air-void system in hardened concrete elements becomes crucial for structures under freezing and thawing cycles. The ASTM C457 standard describes some procedures to accomplish this task, but they are not easy to apply, require specialised equipment, such as a stereoscopic microscope, and result in highly tedious tasks to be performed. This paper describes an alternative procedure to the modified point-count method that is described in the Standard that makes use of macro photography. This alternative procedure uses macro-photographic images that can be obtained with a quite standard photo camera and it is successfully applied to a large set of samples and presents some advantages over the traditional method, since the required equipment is less expensive and provides a more comfortable and less tedious procedure for the operator.

scholarly journals Salt Scaling of Pervious Concrete: Optimizing a Test Method and The Effects of Different Deicers

2021 ◽  
Author(s):  
Chehong Tsang
Keyword(s):  
Mass Loss ◽  
Failure Criterion ◽  
Cycle Length ◽  
Test Methods ◽  
Standard Test ◽  
Test Method ◽  
Pervious Concrete ◽  
Sample Geometry ◽  
Standard Test Method ◽  
Salt Scaling

There is currently no standard test method for evaluating the resistance of pervious concrete to salt scaling. In this study, a number of test methods were evaluated to determine an effective test method. A number of parameters were varied, including sample geometry, cycle length, level of submersion, and the effects of various deicers. The optimum cycle length was found to be 24 hours with the submersion of the bottom 10 mm of the pervious concrete samples made with 14 mm aggregate. Cylinder samples with a diameter of 100 mm and height of 150 mm are recommended as they provide consistent results. Using these samples, a mass loss failure criterion of 3 to 5% is proposed. The deicers that caused the most damage are NaCl, CaCl2, and urea, followed by MgCl2, K acetate, Na acetate, and CMA. More testing is needed to validate the effects of different deicers. i

scholarly journals Development of a Test Method to Evaluate Durability of Pavement Joints under Winter Conditions

2021 ◽  
Author(s):  
Conrad Babicz
Keyword(s):  
Visual Inspection ◽  
Strength Loss ◽  
Standard Test ◽  
Test Method ◽  
Concrete Slabs ◽  
Freezing And Thawing ◽  
Premature Failure ◽  
Different Types ◽  
Evaluation Techniques ◽  
Different Levels

In areas with cold winters, premature failure in concrete pavement joints is a frequent phenomenon, yet there is no standard test method for evaluating their durability. In this study, the effectiveness of several evaluation techniques for concrete joint durability were evaluated. Concrete slabs with saw cuts representing joints were made, and exposed to different freezing and thawing/ wetting cycles, and different salt solutions (NaCl, CaCl2, and MgCl2). The durability of the joints was evaluated using measures of strength loss, mass loss, and a visual inspection. It was found that under these exposure conditions, the strength loss and visual inspection modes of evaluation could discern different levels of damage between different types of exposures, and also different concrete mixes (e.g. Different cement contents, strength and the presence or absence of SCM). Further research is required to evaluate the effects of sealants, saturated bases, and higher salt concentrations.

scholarly journals Salt Scaling of Pervious Concrete: Optimizing a Test Method and The Effects of Different Deicers

2021 ◽  
Author(s):  
Chehong Tsang
Keyword(s):  
Mass Loss ◽  
Failure Criterion ◽  
Cycle Length ◽  
Test Methods ◽  
Standard Test ◽  
Test Method ◽  
Pervious Concrete ◽  
Sample Geometry ◽  
Standard Test Method ◽  
Salt Scaling

There is currently no standard test method for evaluating the resistance of pervious concrete to salt scaling. In this study, a number of test methods were evaluated to determine an effective test method. A number of parameters were varied, including sample geometry, cycle length, level of submersion, and the effects of various deicers. The optimum cycle length was found to be 24 hours with the submersion of the bottom 10 mm of the pervious concrete samples made with 14 mm aggregate. Cylinder samples with a diameter of 100 mm and height of 150 mm are recommended as they provide consistent results. Using these samples, a mass loss failure criterion of 3 to 5% is proposed. The deicers that caused the most damage are NaCl, CaCl2, and urea, followed by MgCl2, K acetate, Na acetate, and CMA. More testing is needed to validate the effects of different deicers. i

scholarly journals Alkali Release from Aggregates in Long-Service Concrete Structures: Laboratory Test Evaluation and ASR Prediction

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1393 ◽  
Author(s):  
Mario Berra ◽  
Teresa Mangialardi ◽  
Antonio Paolini
Keyword(s):  
Calcium Hydroxide ◽  
Concrete Structures ◽  
Weight Ratio ◽  
Standard Test ◽  
Test Method ◽  
Test Duration ◽  
Alkali Extraction ◽  
Proposed Model ◽  
Leaching Solution

This paper proposes a simple model for predicting the development of deleterious expansion from alkali-silica reaction (ASR) in long-service concrete structures. This model is based on some composition and reactivity parameters related to ASR, including the long-term alkali contribution by aggregates to concrete structures. This alkali contribution was estimated by means of a laboratory extraction test, appositely developed in this study in order to maximize the alkali extraction within relatively short testing times and with low leaching solution/aggregate ratios. The proposed test is a modification of the Italian Standard test method UNI 11417-2 (Ente Nazionale Italiano di Normazione) and it consists of subjecting an aggregate sample to leaching with saturated calcium hydroxide solution in a laboratory autoclave at 105 °C. Nine natural ASR-susceptible aggregates (seven sands and two coarse aggregates) were tested and the following optimized test conditions were found: leaching solution/aggregate weight ratio = 0.6; solid calcium hydroxide/aggregate weight ratio = 0.05; test duration = 120 h. The results of the optimized alkali extraction tests were used in the proposed model for predicting the potential development of long-term ASR expansion in concrete dams. ASR predictions congruent with both the field experience and the ASR prevention criteria recommended by European Committee for Standardization Technical Report CEN/TR 16349:2012 were found, thus indicating the suitability of the proposed model.

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