• Magazine of the Korea Concrete Institute
• /
• v.8 no.6
• /
• pp.163-172
• /
• 1996

Recently, the disposal of used vehicle tires is a big social problem because the amount of used vehicle tires has been increased with development of' automobile industry. Many researches have been made on the recycling of used vehicle tires in the various fields of industry as well as construction industry. When the crumb rubber made of vehicle tires is mixed in cement concrete and mortar, it is indicated that the adhesive strength of interface between the crumb rubber and cement hydrates is very low. The purpose of this study is to improve the fundamental properties by increasing of the adhesion strength of styrene-butadiene rubber(SF3R) latex coated crumb rubber in ; cement mortar. SBR-modified mortar using crumb rubber is also tested as the same method. From the test results, the cement mortar using SBR latex coated crumb rubber have a good fundamental properties compared with that using uncoated crumb rubber. The mechanical properties of SBR-modified mortar using crumb rubber with polymer-cement ratios of 10% are also improved.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.10a
• /
• pp.51-57
• /
• 1996

The purpose of this study is to improve the properties by increasing of the adhesion strength of styrene-butadiene rubber(SBR) latex coated powdered rubber in cement mortar. SBR-modified mortar using powdered rubber is also tested as the same method. From the test results, the cement mortar using SBR latex coated powdered rubber have a good mechanical properties compared with that using uncoated powdered rubber. The mechanical properties of SBR-modified mortar using powdered rubber with polymer-cement ratios of 10% are also improved.

• Applied Chemistry for Engineering
• /
• v.29 no.4
• /
• pp.399-404
• /
• 2018

This study compared the tackiness and adhesion of different tire tread compounds and rubber cements before and after vulcanization. The tackiness of natural rubber (NR) cement was the highest for all tread compounds before vulcanization, and the decrease in tackiness of NR cements over time was smaller than that of synthetic rubber cements. The tackiness before vulcanization was affected by the glass transition temperature of the rubber used in the cement and the decrease in tackiness over time of NR was smaller compared to that of using the synthetic rubber. The adhesion of NR-based cements after vulcanization was high for NR tread compounds but low for synthetic rubber tread compounds. On the contrary, the adhesion of emulsion (SBR) and solution SBR cements was high on all tread compounds which was shown to be higher when the rate of vulcanization of cement rubber was lower.

• Korean Journal of Microbiology
• /
• v.12 no.3
• /
• pp.147-148
• /
• 1974

A small amount of Duco cement or Elmer's clear cement was dropped on a slide glass and immediately spread with a glass rod or woden stick a thin film on the surface. After approximately 1 minute a small amount of rubber cement was spread on the top of the film of Duco cement using the same method as described earlier. It was important that the rubber cement be smeared before the Duco cement dried out. These two kinds of cements must not be mixed. It was better to make the film of the rubber cement slightly thicker than the film of Duco cement. This composite film may be used up to several months after preparation. The sample leaf was placted on the slide, prepared with adhesive and the leaf surface was passed on the film with the thumb. The pressing was done so the leaf surface was completely in contact with the film. Then the leaf was peeled from the slide.

• Computers and Concrete
• /
• v.11 no.1
• /
• pp.63-73
• /
• 2013

In this study, the effect of reducing cement by proportional addition of waste powder rubber on the performance of concrete under impact three-point bending loading were investigated experimentally and numerically. Concrete specimens were prepared by adding 5%, 10% and 20 % of rubber powder as filler to the mix and decreasing the same percentage of cement. For each case, three beams of $50mm{\times}100mm{\times}500mm$ were loaded to failure in a drop-weight impact machine by subjecting them to 20 N weight from 300mm height, while another three similar beams were tested under static load. The bending load-displacement behavior was analyzed for the plain and rubberized specimens, under static and impact loads. A three dimensional finite-element method simulation was also performed by using LUSAS V.14 in order to study the impact load-displacement behavior, and the predictions were validated with the experimental results. It was observed that, despite decreasing the cement content, the proportional addition of powder rubber until 10% could yield enhancements in impact tup, inertial load and bending load.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1991.10a
• /
• pp.99-106
• /
• 1991

Result of an experimental study on the manufacture, the mechanical properties and waterightness of pitch-based carbon fiber reinforced fly ash.cement composites are presented in this paper. The carbon fiber reinforced fly ash.cement composites using early strength cement, silica powder and a small amount of stylene butadiene rubber latex are prepared with carbon fiber, foaming agents and mixing conditions. As a result, the mechanical and plysical properties such as compresive, tensile and flectural strengths, watertightness and cement composites are improved by using a small amount of stylene butadiene rubber latex.

• Advances in concrete construction
• /
• v.11 no.5
• /
• pp.409-417
• /
• 2021

The incorporation of non-biodegradable tyre waste in cement-based material has gained more interest towards sustainable construction these days. Crumb rubber (CR) from waste tyre is an alternative for sand replacement in low strength applications. Many researchers have studied CR cement-based materials produced by normal mixing (NM) method and reported a significant decrease in compressive strength due to CR. To compensate this strength loss, this research aims to study the innovative incorporation of CR in cement composite via the preplaced mixing (PM) method. In this investigation, cement composite was produced with NM and PM methods by replacing sand with 0%, 50%, and 100% CR by volume. The test results showed no significant difference in terms of densities of cement composite prepared with both mixing methods. However, cement composite prepared with PM method had lower strength reduction (about 10%) and lowered drying shrinkage (about 20%). In addition, the sound absorption coefficient and noise reduction coefficient of CR cement composite prepared by PM method were in similar range as those prepared with NM method. Overall, the results demonstrate that the PM method is promising, and the maximum replacement level of 50% is recommended for CR in the cement composite.

• Applied Chemistry for Engineering
• /
• v.5 no.5
• /
• pp.786-794
• /
• 1994

The strength and durability of polymer-cement mortars were investigated. The specimens of polymer-cement mortar were prepared by using styrene-butadiene rubber(SBR) latex, ethylene-vinyl acetate(EVA) emulsion and polyacrylic ester(PAE) emulsion with various polymer-cement ratios(5, 10, 15, 20wt%). For the evaluation of durability of polymer-cement mortars, freezing-thawing, acid resistance and heat resistance tests were conducted. With an increase of polymer-cement ratio, the frost resistance of polymer-cement mortars was greatly improved, but acid and heat resistance were deteriorated. The compressive and flexural strengths of SBR polymer-cement mortars were improved with an increase of polymer-cement ratio, whereas those of EVA and PAE polymer-cement mortars reached maximum value at polymer-cement ratio of 10wt%.

• Advances in concrete construction
• /
• v.4 no.1
• /
• pp.49-69
• /
• 2016

This work investigates the mechanical properties of conventional concrete (CC) and self compacting concrete (SCC) using fine rubber and silpozz were accompanied by a comparative study between conventional rubberized concrete (CRC) and self compacting rubberized concrete (SCRC). Fine rubber (FR) from scrap tires has replaced the fine aggregate (FA) and Silpozz has been used as a replacement of cement at the proportions of 5, 10 and 15%. Silpozz as a partial replacement of cement in addition of superplasticiser (SP) increases the strength of concrete. Fresh concrete properties such as slump test, compaction factor test for CRC, whereas for SCRC slump flow, $T_{500}$, V-funnel, L-box, U-box, J-ring tests were conducted along with the hardened properties tests like compressive, split tensile and flexural strength test at 7, 28 and 90 days of curing. The durability and microstructural behavior for both CRC and SCRC were investigated. FR used in the present study is 4.75 mm passing with fineness modulus 4.74.M30 grade concrete is used with a mix proportion of 1:1.44:2.91 and w/c ratio as 0.43. The results indicate that as FR quantity increases, workability of both CRC and SCRC decreases. The results also show that the replacement of natural fine aggregate (NFA) with FR particles decreases the compressive strength with the increase of flexural strength observed upto 5% replacement of FR. Also replacement of cement with silpozz resulted enhancement of strength in SCRC.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.319-322
• /
• 1999

The adhesion properties of polymer cement mortars for cement concrete repair were evaluated with respect to polymer-cement ratios and the surface conditions of cement concrete substrate. Styrene-butadiene rubber (SBR) was used as an additive for polymer cement mortars. The adhesion strength of cement mortar was smaller than that of polymer cement mortar. The adhesion strengths to the dry surfaces of substrate were larger than those to the wet surfaces, indicating that the dryness of substrate increased the adhesion strength in repairing concrete structures.