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Admixture for Concrete. P umice. Nowadays one of the most using construction material is concrete.However Normal concrete is produced water cement agreagate and having different properties of admixtures.
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Admixture for Concrete Pumice
Nowadays one of the most using construction material is concrete.However Normal concrete is produced water cement agreagate and having different properties of admixtures. • Normal concrete have too many unit volume weight.This disadvantage caused by important problems.
Long spans beams can not carry own weight and this element buildings more damaged from earthquake. • Light concrete is produced for prevent to this disadvantage.It is provide decrease %20-25 unit volume weight from concrete. • Also using light concrete provide this advantage • ---economy because sections are smaller • ---Heat and sound insularation • ---Fire resistant • ---Strength is high against earthquake
According to Turkish Standart Pumice:apperiance like sponge and voids not connected each other occur from mostly silicate, volcanic natural light stone with a unit weight of less than 1g/cm^3, hardness of aproximately 6 according to mohs scale and showing glass texture.The purmice aggregate contain approximately %70 space.
Formation of Pumice • Pumice rock forms when the magma cools so quickly that atoms in the melt are not able to arrange themselves into a crystalline structure.
Physical Properties of Purmice • Pumice Stone float on water. • Pumice Stone commonly originated from Indonesia and Turkey. • Different sizes of Pumice Stones are available. such as: • 2-5 cm which known as small Pumice Stone. • 3-5 cm which known as medium size Pumice Stone. • 5-7cm which is known as Large size Pumice Stone. • The melting temperature of Pumice Stone is 15000˚ C. • pH value is 8 .
Physical Properties of Purmice • Hardness:6 • Grain Size:Fine Grained • Porosity:High Porous • Streak:White, Greenish white or Gray • Compressive strenght:52,20 N/mm^2 • Density:2,313 g/cm^3 • Specific Gravity:2,86 • Unit weight:1g/cm^3
Chemical Properties of Purmice • Pumice include amount of %75 silica • Chemical components of pumice are: • %60-75 SiO2 • %15-17 Al2O3 • %1-3 Fe2O3 • %1-2 CaO • %7-8 Na2O-K2O
Chemical Properties of Pumice • SiO2gives corrosive property to pumice. • Al2O3 compound is gives high strength property to pumice against fire and heat.
There are two types of punice • 1)Bazik pumice(white) • 2)Acidic pumice(brown, black)
Punice is a puzzolan that when suitable amount of pozzolan is used with concrete instead of aggregate, concrete gains bindingness properties more than normal concrete. • But using suitable amount is very important if use too much than concrete can lose strength. • We can see it in these graphics.
Pumice in the construction sector; • Production of lightweight structural elements • In the production of prefabricated building elements, • Roof and decorative covering elements production, • In light ready plaster and mortar production, • In light concrete production, • It is used frequently in roof and floor insulation filling.
Resources • Alduaıj, J., Alshaleh, K., Haque, M. N., Ellaıthy,K., 1999, Lightweight concrete in hot coastalareas, Cem. Concr. Compos. 21, 453-458. • Altun, F., Haktanir, T., 2001, Flexural behavior ofcomposite reinforced concrete elements, J.Mater. Civ. Eng. ASCE., 13, 255-259. TS 706, 1980, Beton Agregalari, Ankara, Turkey. Nevşehir Pomzasınm Agrega Olarak Betonda Kullanılabilirliğinin Araştırılması- A. Tolğay, E. Yaşar & Y. Erdoğan Çukurova Üniversitesi, Maden Mühendisliği Bölümü, Adana KSU Mühendislik Bilimleri Dergisi, 16(2),2013 Osman GEÇTEN, Rüstem GÜL Atatürk Üniversitesi, İnşaat MühendisliğiProgramı, Erzurum, Türkiye