Underwater Abrasion Research Articles

Underwater surface abrasion of conventional and geopolymer concrete using the ASTM C1138 approach

This study focuses on the development of unique geopolymer-based composites made using industrial byproducts and waste materials. The first test variable was the compressive strength grade, where conventional concrete specimens with ordinary Portland cement (OPC) and GPC specimens having three target design strengths (20, 30 and 40 MPa) were prepared and tested. All specimens were tested at different ages, which is the second variable of the study, where early ages (3 and 7 days) and mature age (28 days) were adopted. It is worth mentioning that both geopolymer and concrete samples had the exact quantities of filler and binder materials. Then, the specimens were tested following the procedure of standard ASTM C1138 approach under-water abrasion tests, which were conducted at 6 intervals of 12 h each. The recorded abrasion results revealed higher abrasion losses for specimens with lower design strengths regardless of the type of concrete. Besides, the influence of the sample's age on enhancing the abrasion resistance was more apparent in conventional concrete samples than geopolymer ones since the last gained their design strength early, about three days. The GPC specimens exhibited lower abrasion losses compared to their corresponding OPC ones revealing a better abrasion resistance. The difference was the highest at the age of 3 days due to the early strength development of GPC. The abrasion resistance enhancement of GPC specimens compared to their corresponding OPC ones at 3 days was 72% for the design strength of 20 MPa and around 55% for the higher design compressive strengths.

A Study on the Abrasion Resistance of Hydraulic Structures with Different Repair Mortars

One of the main problems with hydraulic structures is that floating silt, gravel, ice sand, boulders, and other materials circulating over a concrete surface have an abrasive effect that causes hydraulic structures to abrade. Abrasion causes concrete to degrade, which could eventually expose the reinforcing to corrosion. In addition to section loss, reinforced concrete hydraulic structures’ endurance may also be a problem. Repair mortars are used to restore surfaces that have been abraded. The suitability of various repair materials for use as a repair layer on concrete surfaces is examined in this study. In order to apply different repair mortars to concrete specimens and subject them to abrasive forces, this work employs an experimental methodology. The ASTM C 1138 standard was followed for testing the abrasion resistance of the samples repaired using repair mortars underwater. Both silica fume mortar and polymer-modified mortar were employed in the study as forms of repair mortar. For each type of repair mortar, three cylindrical concrete specimens were cast, along with control specimens. Hence, nine cylindrical concrete samples in total were employed in this study. In order to quantify the effect of abrasion and, consequently, to assess the efficacy of various repair materials, abrasion volume loss was measured. Important findings about each type of repair material’s resistance to underwater abrasion are included in the study. The findings show that in terms of abrasion resistance underwater, the polymer-modified mortar performs better than the silica fume mortar.

Development and Performance Evaluation of Rotary Underwater Abrasion Tester

Development and Performance Evaluation of Rotary Underwater Abrasion Tester

A simple suggested approach to reduce the testing time of concrete surface abrasion using ASTM C1138

The ASTM C1138 standard underwater abrasion test can be considered as the best available experimental tool to qualitatively evaluate the abrasion resistance of concrete surfaces in hydraulic structures. It introduces an accelerated test procedure to simulate the high speed motion of water and waterborne materials on concrete surfaces. However, the test period is relatively long, which is composed of 6 time steps of 12 h each, totaling a complete 72 testing hours for each sample. Thus, although of the simple test procedure and good potential to simulate real abrasion in hydraulic structures, it is difficult to perform and requires a long time if many concrete samples are needed to be compared. At the aim of investigating the possibility of reducing the total testing time of ASTM C 1138, an experimental work was conducted in this research. Three concretes with low strength (LSC), normal strength (NSC) and high strength (HSC) were tested at different rotational speeds of 800, 1200 and 1600 rpm. The test results showed that increasing the test speed from the standard 1200 rpm–1600 rpm resulted in an average increase in an abrasion weight loss of 42.6–47.0%, which encourages the possibility of reducing the total testing time by 40 % if the test is performed at a speed of 1600 rpm. The test results of this study and others from the literature showed that the relationship between the abrasion weight loss and testing time (up to 72 h) can adequately be represented using a linear correlation. The R2 values of the linear correlations of 16 different concrete mixtures ranged from 0.936 to 0.999. Based on the obtained results, a simplified modified test procedure was suggested to reduce the total testing time from 72 h to 15 h.

OPTIMIZING MIXTURE OF SELF-COMPACTING CONCRETE FOR CONSTRUCTING A SPILLWAY SURFACE STRUCTURE

A spillway apron is a popular hydraulic work with congested reinforcement and complex shapes. Self-compacting concrete (SCC) with excellent workability can meet the technical requirements for the work. This study focuses on determining the SCC optimal mix for efficient use of local coarse aggregates and 100% crushed sand to construct a spillway surface structure. For the purpose, research steps were carried out as follows: (1) optimize mix ratio of coarse aggregates ; (2) determine the saturatedcontent of superplasticizer, (3) design SCC preliminary mix; (4) set up an experimental plan; and (5) analyzetest data to point out the optimal SCC mix.The investigation of fresh SCC was conducted by slump flow test, slump flow time test,L-box test, and segregation resistance test. Compressive strength, watertightness, and underwater abrasion of hardened SCC were also evaluated. The abrasion tests follow the ASTM C1138-19 method and Yu-Wen Liu’s method.The results show that the optimal SCC with slump-flow of 72 cm, the H2/H1 ratio of 0.85, compressive strength at 28 days of 42.5 MPa,abrasion resistance of 0.34 g/cm2; and watertightness of B10 meets specifications of a spillway surface structure. Besides, the abrasion depth measured by Yu-Wen Liu's method of water-borne sand was about four times greater than that of ASTM C1138-19.

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

Underwater abrasion of steel fiber-reinforced self-compacting concrete

Hundreds of tons of concrete may be ruined due to the abrasion erosion phenomenon that takes place in several hydraulic structures. Such unfavorable action can impose high maintenance costs and reduce the life span of these structures. The high-velocity water flow which carries large amounts of sediments is basically the main cause of this phenomenon. To better understand concrete abrasion in hydraulic structures, an experimental investigation was conducted to study the underwater frictional abrasion of self-compacting concrete (SCC) using the ASTM C1138 test method. Six SCC mixtures were prepared with different design grades of 30, 40 and 50 MPa and different micro-steel fiber contents of 0, 0.5, 0.75 and 1.0%. Four fresh SCC tests were adopted, while abrasion and control tests were conducted at ages of 7, 28 and 90 days. The ASTM C1138 tests showed that increasing the mixture strength by 20 MPa improved the abrasion resistance more effectively than the inclusion of 1.0% of steel fiber. Compared to the 30 MPa plain SCC, the 90-day abrasion resistance improved by 78% for SCC with 50 MPa strength, while the inclusion of 1.0% of micro-steel fiber enhanced the resistance by only 26%.

Development of an automated underwater abrasion rig to determine galvanic effects during the growth and localised breakdown of surface films in CO2-containing solutions.

This paper outlines the development of an automated underwater abrasion rig to assist in understanding the galvanic interaction induced by surface films when continuous localised mechanical film breakdown is encountered on the surface of carbon steel in CO2-containing environments. The rig enables the measurement of galvanic current between a small X65 steel pin and a larger steel specimen, as well as the intrinsic corrosion rate of an additional, uncoupled larger specimen. The surface film developed on the pin is removed periodically using an automated reciprocating and rotating shaft with a sand paper grit pad attached to the base, while the surface film is allowed to establish itself undisrupted on the large specimen. The setup essentially simulates a tribo-corrosion process where local removal of material occurs within a carbon steel pipeline as a result of periodic sand particle impingement. Initial results focus on validating the reproducibility of the technique, as well as determining the galvanic effects associated with iron carbide and iron carbonate for two model sets of conditions to highlight the capabilities of the system.

Resistance to sulfate attack and underwater abrasion of fiber reinforced cement mortar

This research was conducted to study the combined effect of sulfate attack and underwater abrasion on fiber reinforced cement mortar. Compared to plain mortar mix, cement mortars reinforced with three types of fiber, i.e. steel fibers, polypropylene fibers, and micro polypropylene fibers were investigated. Each fibers was used individually and the micro polypropylene was additionally hybridized with steel and polypropylene fibers. Test specimens were prepared as per ASTM C1138. Their abrasion resistance were examined after submersed in 5% sodium sulfate (Na2SO4) solution for 4 and 8 months. The experimental results showed that the Na2SO4 solution increased the weight loss of all specimens. The longer the period of submersion, the higher the weight loss. In the specimens reinforced with fibers, the abrasion resistance was enhanced. The highest resistance was found in the mortar mixed with the polypropylene fiber at 1% volume fraction. Moreover, in abrasion resistance point of view, the addition of micro polypropylene fiber had little or no benefit.

Experimental tests on the underwater abrasion of Engineered Cementitious Composites

The abrasion of Engineered Cementitious Composites (ECC) due to waterborne materials in hydraulic structures was investigated using the ASTM C1138 abrasion test method. The test specimens were divided into two groups, the first was directed to study the effect of the PVA fiber content, while the second investigated the effect of the ECC covering layer thickness. The tests were conducted at ages of 3, 7 and 28 days. The test results showed that the abrasion resistance increases as PVA content increase. At an age of 28 days, incorporating low PVA contents (0.5% and 1.0%) increased the abrasion resistance by approximately 20%, while the inclusion of high PVA contents (1.5% and 2.0%) improved the abrasion resistance significantly with percentage improvements ranging from 50 to 95%. The percentage abrasion weight losses after 72 testing hours at this age were 7.6, 5.9, 4.7, 3.6 and 2.4% for fiber contents of 0, 0.5, 1.0, 1.5 and 2.0%, respectively. The test results also showed that covering of normal concrete with 1 cm layer of ECC is not effective during the early age of this material, while a layer of 3 cm thickness showed good abrasion resistance at early and mature ages.

Underwater Abrasion Resistance of Cementitious Acrylic Coating on Repaired Surface of Concrete Dam and Stilling Basin

The paper presents and analyzes the results of the underwater abrasion tests of Cementitious Acrylic Coating (CAC), which was used to protect the repaired surface of concrete dam and stilling basin of power-plant Moste on river Sava in Slovenia. Behavior of the CAC obtained with laboratory tests is rather similar to the behavior obtained after 1 year of application on the power-plant. Relatively good underwater abrasion resistance of CAC was obtained. Results of bond strength show that pressure of capillary water decreases bond between CAC and concrete surface. If such coating is additional loaded with abrasion forces, bond between those two layers becomes worse. Similar conclusions can be made on the basis of the obtained results of surface resistance to freeze-thaw test of CAC has been carried out. The resistance is rather good, but CAC separated from concrete surface, when water is present in the interface between the CAC and concrete surface during freeze-thaw loading.

Resistance to Underwater Abrasion of Fiber Reinforced Cement Mortar

Surfaces of hydraulic concrete conduits where significant abrasion of waterborne sediment can occur often degrade and need a regular repair to maintain their serviceability. In this research, thin overlay made of fiber reinforced cement mortar was introduced as a repair measures. Its resistance to underwater abrasion was therefore experimentally evaluated following the procedures of ASTM C 1138. This research utilized three types of fiber: steel fiber, polypropylene fiber, and micro polypropylene fiber (the micro polypropylene fiber was used only in a combination with either the steel or the polypropylene fiber). The influence of these fibers on the abrasion resistance of fiber reinforced cement mortar was then determined in terms of weight loss. The weight loss results showed that the fibers added to mortar specimens can enhance the abrasion resistance. Between the steel and polypropylene fiber, the latter provided better abrasion resistance. In case of the combination mixes, the micro polypropylene fiber increased abrasion resistance when combined with the polypropylene fiber but had no benefit when combined with the steel fiber.

Three-Dimensional Characterization of Concrete’s Abrasion Resistance Using Laser Profilometry

This paper presents development of three-dimensional characterization of concrete abrasion using the ASTM C1138 test method, which simulates underwater abrasion. To this effect, a measuring system was designed based on laser triangulation with linear illumination of the surface measured. The system allows for contactless, quick and precise measuring of average wear and other topological characteristics dependent on the type of the tested concrete. Validation results show that the system’s precision is better as conventional weighting method (<15 gram) and furthermore it allows us to analyze the spatial distribution of wear.

A topology measurement method examining hydraulic abrasion of high workability concrete

This research concerns the abrasion resistance of high workability concrete with various amounts of Supplementary Cementitious Materials (SCM). Various factors affect abrasion resistance, including the strength of concrete, water-binder ratio, amount of SCM, surface finishing, degree of aggregate exposure, and severity of the abrasive loading. An underwater abrasion test method, in which specimens are sectors of a circle, was newly proposed based on the modification from a typical method for simultaneous comparison of the abrasion resistance of concrete of differing mix proportions. Abraded concrete volumes were determined using a non-contact 3D measurement system. It was found that initial surface irregularities affect the development of ensuing erosion. Concrete containing more fly ash showed less abrasion erosion resistance at early age. Concrete mixed with blast-furnace slag showed higher abrasion resistance for approximately 20% replacement of cement, within the test range of 0∼60%. In addition, the abrasion resistance increases as the aggregate exposure ratio increases for concrete with fly ash.

Performance of Concrete Incorporating Stone Industry Waste as Aggregates

Scarcity of nonrenewable natural resources is stipulating the adoption of global sustainable approaches to ensure better utilization of resources. Abrasion mechanisms take place on concrete surfaces, such as pavements and hydraulic structures, as a result of mechanical wear, scour, erosion, and cavitation. Adequate attention has not been paid to the incorporation of coarse aggregate by-products from the stone industry in concrete used for building transportation infrastructures. This paper evaluates the performance of concrete mixtures that incorporate coarse aggregate by-products of the stone industry for their resistance to abrasion. Twenty-four concrete mixtures were prepared with two types of granite and one type of basalt coarse aggregates procured from the waste of stone processing factories in Egypt. Two coarse aggregate sizes were used: 9.5 and 19 mm. The three mixture sets were compared to a control set prepared with dolomite as coarse aggregate. Fresh and hardened concrete tests as well as two abrasion tests were conducted to evaluate mechanical wear and underwater abrasion resistance of the concrete. The results revealed that the stone by-products were suitable for concrete used in highly abrasive environments. Some mixtures, such as the one made with gray granite, had superior strength as well as enhanced abrasion resistance. Such by-products are underutilized by the applicators. It is recommended that this work be further pursued on a wider scale with greater focus on economical and environmental merits as well as other long-term properties.

On the Extraneous Fossils of the Red Crag

The Deposit called the Red Crag indicates the action of strong reversible or tidal currents, and is more disturbed and littoral in its character than any portion of a formation at present known; and, for its limited area, it contains a larger percentage of foreign† organic remains than any of which we have as yet a record. I know of no locality that appears to me more to resemble what was probably the local condition of the Sea of the Red Crag during the accumulation of the material herein enumerated than the conditions under which the Bay of Christchurch at present exists; and I believe that in the conflicting streams that now wash the shores of that neighbourhood may be found a cause sufficient to produce all the effects visible in the Red Crag,—only reversing the direction of the land, the sea of that period opening to the northward. To ascertain the age of the Red Crag by the “percentage test,” could only be effected by the exclusion of a large portion of its contents; and, when we have got rid of those fossils which we know to belong to some remote anterior period, we should then have to contend against the doubtful admission of many species that may have been introduced from the deposits immediately antecedent. A large number of the shells have in all probability, as suggested by Sir Charles Lyell, been washed into the Red Crag Sea by an underwater abrasion of the older beds; and the