• Journal of Industrial Technology
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• v.22 no.A
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• pp.161-168
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• 2002

Latex modified concrete is governed by both cement hydration and polymer film formation processes in its binder phase. Such the reactions are expected to improve the polymer-cement co-matrixes themselves and the bond between the cement hydrates and aggregates, and to improve the properties of hardened latex-modified concrete. The purpose of this study was to study the strength and chemical resistance of Rapid-setting latex modified concrete(RSLMC) with the main experimental variables such as latex content(0, 5, 10, 15, 20%) and water-cement ratio(36, 38, 40%) at latex content 15%. Water absorption test was earned out to estimate water permeability resistance. Chemical resistance test was carried out to measure the weight change and to observe the appearance of RSLMC immersion in hydrochloric acid, sulfuric acid, and calcium choloride.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.139-146
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• 2006

Many concrete bridge decks develop transverse cracking shortly after construction. These cracks accelerate corrosion of reinforcing steel and lead to concrete deterioration, damage to components beneath the deck, unsightly appearance. These cracks shorten the service life and increase maintenance costs of bridge structures. In this study, VES-LMC overlay, which provides the same benefits as a conventional overlay, is designed to cure very quickly. Although the materials for VES overlays are more expensive, the cost is more than offset by the savings on traffic control and work zone safety measures. Otherwise, reaction of hydration occurs very rapidly in beginning step(concrete placing). As a results, thermal cracking can be occur by thermal stress in accordance with hydration-heat The purpose of this study was to estimate diagnosis of crack occurrence of VES-LMC through field tests at early-age.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.559-567
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• 2005

The objective of this study is to optimize the use of mineral admixtures (silica fume, fly ash, and blast furnace slag) in high-performance concrete for bridge deck overlay. For this purpose, high-performance concrete, incorporating mineral admixtures, was tested for compressive strength and permeability. The Box Behnken design was used to determine the optimum mix proportions of the mineral admixtures. The optimized mix compositions were then technically evaluated. Test results are compare with the performance specification for high performance concrete overlay on bridge deck. The optimum mix proportions were shown to possess acceptable properties. Also, it is possible to save the construction and materials costs result from a reduction In actual material cost and from the use of widely avaliable truck mixers instead of mobile mixers.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.193-200
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• 2002

Drying shrinkage cracking which may be caused by the relatively large specific surface IS a matter of grave concern for latex modified concrete(LMC) overlay and rapid-setting cement latex modified concrete(RSLMC) overlay. LMC and RSLMC were studied for field applications very actively in terms of strength and durability in Korea. However, there were no considerations in drying shrinkage. Therefore, the purpose of this dissertation was to study the drying shrinkage properties of LMC and RSLMC with the main experimental variables such as cement types(ordinary portland cement, rapid setting cement), water-cement ratios and curing days at a same controlled environment of 60% of relative humidity and $20^{\circ}C$ of temperature The drying shrinkage for specimens was measured with a digital dial gauge of Demec. The test results showed that the drying shrinkage of LMC and RSLMC were considerably lower with low water-cement ratio, respectively This might be attributed to the interlocking of hydrated cement and aggregates by a film of latex particles, water retention due to hydrophobic, and colloidal properties of the latexes resulting in reduced water evaporation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.503-510
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• 2009

Latex modified concrete (LMC) is a successful polymer-portland cement concretes, which have been developed and used for many years, in overlaying bridge decks and resurfacing industrial floors. The excellent bond strength to substrate, easy application and high resistance to impact, abrasion, wear, aggressive chemicals and freeze-thaw deterioration have made this material used widely. The objective of this study was to determine experimentally the load-deflection response and ultimate strength of reinforced RC beams. The cracking patterns and the mode of failure were observed. Because of excellent bond strength and repairing effects, the RC beams repaired by LMC at compression or tension zone showed over 100% recovery from damaged structures. The RC beams overlaid by LMC showed significant improvement at load carrying capacity as overlay thickness increases. However, the beams repaired of tension zone without shear stirrups almost showed no strengthen effect, and indicated an interfacial failures. The interfacial behavior was estimated by numerical method adopting the concept of shear flow.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1023-1028
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• 2001

This study focused on the investigation of strength development and permeability of LMC(latex modified concrete) and RSLMC(rapid-setting cement latex modified concrete) as the latex content, cement types and w/c ratio variated. The compressive strength of latex modified concrete decreased slightly and the flexural strength increased quitely at the latex content of 15%. This may due to the flexibility of latex filled in voids and interconnections of hydrated cement and aggregates by a film of latex particles, respectively. The permeability test results showed that the permeability of LMC was considerably lower than that of conventional concrete. In the RSLMC's tests of permeability to chloride ion indicated very low permeability at an early age, which nay be due to the early formation of needle-shape ettringites and latex film.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.569-572
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• 2006

This study was performed to investigate the characteristics of carbonation for latex modified concrete with fly ash and blast furnace slag. The experimental variables consisted of ground granulated blast-furnace slag contents (0%, 30%, 50%), fly ash contents (0, 30%) latex contents (0, 5, 10, 15%). Two different methods of carbonation test such as $CO_2$ gas and 5% sulphuric acid digestion resistance test were varied in this study.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.289-292
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• 2006

The purpose of this study was to evaluate a performance of latex-modified repair material applied to the substrate concrete. The experimental variables were latex-cement ratios (5, 10, 15%), polymer(0.5%, 1%) and admixtures. The flow, air content, compressive strength, flexural strength were tested. Test results showed that compressive and flexural strength decreased by adding hydroxyethyl cellulose and increasing water-binder ratio. The compressive and flexural strength were increased when addition of defoamer.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.769-772
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• 2004

Very-Early-Strength Latex-Modified Concrete(VESLMC) provides the repairing material with short curing time as well as excellent bond strength, flexural strength and impermeability against water and chloride. In 2001, VESLMC introduced in Korea and improved superior material through research and development on material properties and durability. In 2003, the field test progressed for study problems of VESLMC field application. This paper introduced equipment improvement for bridge deck repair save both repair time and labor, while producing quality VESLMC structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.445-448
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• 2004

Recently, bridge deck overlay with latex modified concrete is widely applied in domestic. the capacity of bridge deck overlay depends on bond state on the surface. factors that have an effect on bond state are clean condition on the surface, absence of surface microcracking, absence of laitance, overlay curing. In this study, it is researched that characteristic of bond strength according to moisture condition on the surface and the removal method of concrete. As a result, it shows high bond strength in dry condition when w/c is $31\%$ and in moisture condition when w/c is $38\%$ respectively. characteristic of bond strength according to the removal method of concrete shows high bond strength when using water-jets rather than jackhammers.