concrete technology 2/1 - aalto · concrete technology 2 rak-82.3131 concrete technology 2 exams:...

Concrete Technology 2/1

Aalto UniversitySchool of EngineeringDepartment of Civil and Structural EngineeringBuilding Materials Technology

Concrete Technology 2

Rak-82.3131 CONCRETE TECHNOLOGY 2

• Lectures: Fridays & Mondays at 12.15–14:00 in lecture room R2

• Calculation exercises: Fridays at 10.15 – 12:00 in lectureroom R2 beginning from 18.9.2015

• Design exercise: Introduction presentation on Monday12.10.2015 at 12.15 – 14:00 in lecture room R2

• Laboratory exercises: To be held on November 2015.Instructions and working group sign up list will appear incourse website MYCOURCES. The report has to be deliv-ered not later than 2.1.2016.


Rak-82.3131 CONCRETE TECHNOLOGY 2

Exams: Check WebOodiExam will not be accepted if

-the design exercise is not approved-laboratory report of the laboratory exercises havenot been handed over acceptably prior to the examdate

CONTENT OF THE COURSE1. Review of the terminology2. Chemistry and hydration of cements

- production- composition and clinker minerals- water demand- heat evolution- hydration reactions- volume of hydration products- cement types

3. Supplementary binders- fly ash and wood ash- calcium carbonate- blast furnace slag- silica fume


CONTENT OF THE COURSE


CONTENT OF THE COURSECalculation exercises

- problems of cement chemistry- review of mix design and special cases- heat treatment of common and massive structures- strength evolution of concrete- high strength concretes, ultra high strength concretes, fast

drying concretes, self consolidating concretes, fiber concretes- quality control and estimation of service life-span

Design exercises1. Production technological design of a precast unit

- building block- facade element or a wall precast unit- tensioned concrete beam- reinforced concrete pile


CONTENT OF THE COURSE

2. Production technological design of an in-situ concreted structure- a massive structure (air-raid shelter, bridge foundation,

foundation of a high-rise building)- design of a structure under corrosive loads

Features to be defined- selection of the binder combination- gradation and other properties of the aggregates- estimation of strength and heat evolution of the structure

during production phases- design of the concrete temperature during the production- allocation and technical design of the whole production process


LiteratureHansen, P. F., The science of construction materials, Springer, 2009. 275 p.Neville, A. M., Properties of concrete, Longman, 1995. 844 p.Hansen, P. F., Haerdeteknologi 1, Portlandcement. Alborg Portland, 1978.138 p.Ramachandran, V. S., Feldman, R. F. & Beaudoin, J. J., Concrete science,treatise on current research. Heyden 1981. 398 p.Ramachandran, V. S., Concrete admixtures handbook. New Jersey 1984.603 p.Rixom, M. R. & Mailvaganam, N. P., Chemical admixtures for concrete.London 1986. 225 p.The concrete society (Ed.), Sprayed concrete, fibrous concrete, lightweightconcrete, Admixtures. Lancaster 1980.Penttala, V., Högman, T., Schreck, J. & Ipatti, A., Korkealujuuksisenbetonin valmistustekniikka. Espoo 1986. 128 p.Penttala, V., Ipatti, A. & Hakala, V., Korkealujuuksisten betonienmekaaniset ominaisuudet. Espoo 1987. 109 p.


LiteraturePenttala, V. Mäkinen, K. & Punkki, J., Korkealujuuksisten betoniensuhteitus. Espoo 1990. 61 p.Skalny, J. (Ed.), Material science of Concrete I-VII. The AmericanCeramic Society. 1989.Klinckowström, P. & Penttala, V., Strength properties of polymer cementconcretes. Espoo 1993. 57 p.Taylor, H. W., Cement chemistry. Wiltshire 1997. 437 p.Hewlett, P. C. (Ed.), Lea’s chemistry of cement and concrete. Bury StEdmunds 1998. 1011 p.Wirtanen, L., Eronen, J., Räsänen, V. & Penttala, V., Lämpötilan jasuhteellisen kosteuden vaikutus betonin kuivumiseen. Espoo 1998. 40 p.Mannonen, P., Penttala, V., Al-Neshawy, F. & Räsänen, V., Itsetiivistyvienbetonien suhteitus, valmistustekniikka ja perusominaisuudet. Espoo 2004.106 p.+app. 16 p.+CD-disc.Cwirzen, A., Penttala, V., Vornanen, C. & Junna, K., Self-compactingultra-high-strength concrete containing coarse aggregates. Espoo 2006.95 p. +app. 34 p.


Terminology of concrete technology

Hydraulic property: The ability of a material to react withwater so that a solid reaction product which is waterproof isformed both in the air and under water

Latent hydraulic property: The hardening process needs anactivator to proceed (Portland cement, Ca(OH)2, alkalies)

Hydration: Joint term for the reactions between a hydraulicbinder and water

Hydration heat: The heat amount liberated during ahydration reactionCement stone (cement paste): A mix of hardened cement andwater


Terminology of concrete technologyPortland clinker: Hydraulic product formed in heating amineral raw material mix in powder form so that the surfaceof the particles is sintered

-calcium oxide CaO-silicon dioxide SiO2

-aluminum oxide Al2O3

-iron oxide Fe2O3

Blast furnace slag: A product having latent hydraulicproperties obtained from the alkali silicate flux by fastcooling in the beginning of iron production in a furnace

-granulated slag (glassy degree > 75%)-pelletized slag (30-70%)-air cooled slag (< 30)


Terminology of concrete technologyBuilding cement (rakennussementti): Hydraulic binder used inbuildings in Finland which together with water binds togetherthe constituents of concrete

Portland cement (CEM I): Building cement which is composedof Portland clinker and no more than 5% of supplementarybinders

Yleissementti (CEM II): Building cement which is composed ofPortland clinker and no more than 35% of supplementarybinders

-CEM IIA (supplem. binders 6-20%, silica fume<10%)-CEM IIA (supplem. binders 21-35%, CaCO3 <10%)


Terminology of concrete technologyBlast furnace slag cement (CEM III): Building cement whichis composed of Portland clinker 20-64% and groundgranulated blast furnace slag 36-80%

Slowly hardening cement: Building cement which fulfillscertain strength requirements at the age of 91 days

Fast hardening cement: Building cement which fulfillscertain strength requirements at the age below 28 days

-”Pikasementti” 3 days-”Rapidsementti” 7 days


Terminology of concrete technology

Setting: The stiffening of cement paste normally after 2-6hours from the addition of water to the mix

Setting time: The time from the water addition to the mix toa designated stiffness of a standard paste composition

Overview on the hydration of binders


Chemistry of Portland cement and hydrationProduction of Portland cement

Main raw materials-calcium carbonate CaCO3

-rock minerals containing-silicon oxide SiO2

-iron oxide Fe2O3

-aluminum oxide Al2O3

Crushing, grinding, and homogenization

Burning in a rotating tube oven up to the sinteringtemperature of 1400-1450 oC clinker


Production of Portland cement

Grinding of the clinker and addition of gypsum (CaSO4)Portland cement

Production methods-dry method-wet method

Dry method1. Crude separation of the rock minerals2. Crude and fine grinding3. Intermediate storage4. Homogenization


Production of Portland cementStockpile method

-the ground lime stone is dispersed in a stock pile intothin layers (700)

-samples are taken periodically-addition of correction minerals-homogenization in silos-preheating

Cemixan method-continuous flow of lime stone-automatic sampling-analysis of the samples every half an hour-computerized addition of correction minerals-homogenization in silos-preheating in cyclones


Production of Portland cement5. Burning in a rotating tube oven

-T 800 oC (calcination) CaCO3 CaO + CO2

very endothermic reaction-600 oC T 1200 oC (belite formation)2CaO + SiO2 C2S exothermic reaction

-T > 800 oC (reactions of aluminate and ferrite phases)Al2O3 + 3 CaO C3AAl2O3 + Fe2O3 + 4 CaO C4AF

-1100 oC T 1450 oC (sintering)Al2O3 and Fe2O3 meltCaO + C2S C3S (alite formation) mildlyendothermic


Production of Portland cement6. Cooling to 200 oC7. Grinding to the desired fineness and addition of gypsum

(CaSO4 . 2H2O) to adjust the setting time of the cement8. Storage

The wet method is much more inferior economically-need for additional drying due to the wethomogenization process

-need a larger rotating oven-the burning process denotes 40-60 % of the totalproduction costs


Clinker minerals

Mineral Formula Composition %CaO SiO2 Al2O3 Fe2O3

Tricalcium silicate 3 CaO SiO2 73.7 26.3 - -Dicalcium silicate 2 CaO SiO2 65.1 34.9 - -Tricalcium aluminate 3 CaO Al2O3 62.3 - 37.7 -Tetracalciumaluminate ferrite

4 CaO Al2O3

Fe2O3

46.2 - 21.0 32.8


Conventions used in cement chemistry


Calcium oxide CaO CSilicon dioxide SiO2 SAluminum oxide Al2O3 AIron oxide Fe2O3 FSulfate SO3

Sodium oxide Na2O NPotassium oxide K2O KWater H2O H

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