• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.125-132
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• 2015

This paper presents an experimental investigation in order to evaluate fresh and hardened properties of LP (Limestone Powder) blended cement concrete. The cement contents of the mixtures are replaced by LP in the range of 10%, 15%, 25%, and 35%, while a control mixture is prepared with only OPC (Ordinary Portland Cement). The fresh concrete properties like slump and air content are similar to those of control mixture up to 35% of replacement ratio of LP, however a delay in setting time is evaluated. The hardened properties including compressive strength, flexural strength, and rapid freezing and thawing resistance shows similar results of control mixture up to 15% of replacement. Relatively lower strength development is evaluated over 25% replacement of LP. For accelerated carbonation test, resistance to carbonation rapidly decreases with increasing LP replacement ratio due to the limited amount of $Ca(OH)_2$. From the study, LP replacement under 15% can be adopted considering reduction of strength and resistance to carbonation.

• Advances in concrete construction
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• v.10 no.6
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• pp.515-526
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• 2020

Cold-mixed asphalt mixture is a widely recommended asphalt pavement materials with potentially economic and environmental benefits. Due to the reduction of natural non-renewable mineral resources, powder minerals with similar properties are considered as new mineral fillers in asphalt mixtures. This study explored the feasibility of using cement to replace natural limestone powder (LP) in emulsified asphalt concrete modified by styrene-butadiene styrene copolymer. The experimental tests, including compressive strength, Marshall stability as well as moisture susceptibility test, were used to investigate the mechanical properties, the Marshall stability, flow value, as well as the moisture damage. In addition, the influence of material composition on the performance of asphalt concrete is explained by the microstructure evolution of the pore structure, the interface transition zone (ITZ), and the micromorphology. Due to mineralogical reactivity of cement, its replacement part of LP improved the mechanical properties, Marshall stability, but it will reduce the moisture susceptibility and flow value. This is because with the increase of the cement substitution rate, the pore structure of the asphalt concrete is refined, the width of ITZ becomes smaller, and the microstructure is more compact. In addition, asphalt concrete with a larger nominal particle size (AC-16) has relatively better performance.

• Advances in concrete construction
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• v.6 no.1
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• pp.69-85
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• 2018

In order to provide sufficient stability and resistance against bleeding and segregation during transportation and placing, mineral admixtures are often used in self-compacting concrete mixes (SCC). These fine materials also contribute to reducing the construction cost and the consumption of natural resources. Many studies have confirmed the benefits of these mineral admixtures on properties of SCC in standard curing conditions. However, there are few published reports regarding their effects at elevated curing temperatures. The main objective of this study is to investigate the effect of three different mineral admixtures namely limestone powder (LP), granulated blast furnace slag (GS) and natural pozzolana (PZ) on mechanical properties and porosity of SCC when exposed to different curing temperatures (20, 40, 60 and $80^{\circ}C$). The level of substitution of cement by mineral admixture was fixed at 15%. The results showed that increasing curing temperature causes an improvement in performance at an early age without penalizing its long-term properties. However the temperature of $40^{\circ}C$ is considered the optimal curing temperature to make economical and high performance SCC. On the other hand, GS is the most suitable mineral admixture for SCC under elevated curing temperature.