Bulletin of the Transilvania University of BraşovCIBv 2015 • Vol. 8 (57) Special Issue No. 1 - 2015

SELF-COMPACTING CONCRETEREALIZED WITH BASIC TECHNOLOGY

AND CONTROL

O. SUSA1, C. BADEA1, L. IURES1, R. CHENDES1, S. DAN1,A. MITE1, M. TIVADAR1

Abstract: The present paper takes into account the usage of limestone fillerand Sika special add mixture in obtaining a performing self-compactingconcrete realized with site ordinary equipments which exist on constructionsite. Compression strength, L box, V funnel and slump flow tests have beenmade and also the smoothness of the resulting surface has been taken intoaccount. The objective of this work was to obtain a versatile mixture using arudimentary free fall mixer and high compressive strength. The final batchwill be used to realize a concrete monument exposed into a village square.

Key words: workability, self-compacting, L box, V funnel, mechanicalproperties

1 Politehnica University of Timisoara, Faculty of Civil Engineering, Romania

1. Introduction

Self-compacting concrete is a veryimportant add-on to the constructionmaterial industry, offering a wide range ofconstruction possibilities [1]. It has theproperty of compacting itself under hisweight, uniformly without the need of avibrating it. This enables the use in variousforms and is a very simple solution todifferent and many problems. It also solvesthe numerous problems regarding thetechnical difficulties of vibrating theconcrete mass, while obtaining thinelements and great detail.

One of the disadvantages of SCC is itscost [2], associated with the use ofchemical admixtures and use of highvolumes of Portland cement, which is notsustainable.

The present paper illustrates theproperties of this special concrete and alsodetails the mechanical results [3-6] of self-compacting concrete by using two

proposed recipes.The self-compacting concrete has the

following properties, unlike the usualconcrete:

low water/cement ratio; high concentration of powder or

fine aggregates; less ratio of thick of big diameter

aggregates; the use of add-mixtures that

modify the viscosity of theconcrete;

the possible use of add mixturesthat modify the workability ofthe final mix and that reduce thewater quantity needed [7]

2. Materials

The materials used for this applicationwere:

portland cement – LafargeCEMII/B-M(-LL) 42,5 N;

Bulletin of the Transilvania University of Brasov • Vol. 8 (57) Special Issue No.1 - 2015154

aggregates from a near by gravepit- with the diameters: 0-4about 50%, 4-8 x 13%, 8-16 x37%;

lime stone filler – 80 kg/ m2; admixture ViscoCrete VF 2011

supplied by Sika (through thekindness of Mr. Zeno Dan);

ordinary water from public net..In Fig.1 we can see the weighing of the

aggregates.

Fig. 1. Aggregates weighing

The concrete was prepared using afreefall mixer- as depicted in Fig.2.

Fig. 2. Concrete mixing

These ingredients and procedures givethe self-compacting concrete the role ofpreserving the cast mould details andreplying them in the concrete mass.

Other properties resulting from theoutlined characteristics are some of thefollowing:

the uniform spread of concretewithout of the need of vibrating;

the capability of passing throughthe highly dens rebar zones.

3. Experimental Work

The goal of this experimental work wasto obtain a versatile mixture using arudimentary free fall mixer (which existson construction site) and high compressivestrength.

The Spread

The spread of concrete mass is used todetermine the ability of self-compactingconcrete to free-flow without anyhindrance. Following this determination ofthe diameter concrete mass spread, whichis a measure of that determination. Thisdetermination is widely used because itallows a correct conclusion on the abilityof self-compacting concrete mass to fill thespaces. The elements required can be seenin Fig. 3. Also this method can provideinformation on the trend of segregation ofconcrete. Fig.4 depicts the results of thetest.

Fig. 3. The cone spread equipment

O. Susa et al.: Self-Compacting Concrete used for building a monument with basic… 155

Fig. 4. The Spread Test

V Funnel Test

By using a V funnel- we can test thecohesively of the concrete. As a result ofthis test we can determine if in the fillingcapacity of the concrete, whose aggregatediameter less than 20 mm. If the completeflow in a short period of time is good, thenthe filling capacity of the mixture issufficient. A great time flow leads to a lowdeformability of concrete mass. The Vfunnel is depicted in Fig. 5.

Fig. 5. The V funnel

The L Box Test

The L box test is used to determine theflow capacity and self-compactingconcrete crossing. Also in this test we candetermine if coarse aggregate stuckbetween rebar, and the tendency towardsthe segregation of concrete. The test isshown in Fig. 6.

Fig. 6. The L box test

The Recipes

The proposed recipes have the followingcharacteristics, as can be seen in Tab.1.

The main difference between the tworecipes is the cement quantity and itsinfluence on the concrete’s performancesand overall strength and durability. Thiscan be seen in Tab.2 – containing the finaldata of the two recipes.

These recipes give the concrete its finalperformances and characteristics. They arethe base of with we can estimate theoverall durability and detail fidelity of theconcrete.

Bulletin of the Transilvania University of Brasov • Vol. 8 (57) Special Issue No.1 - 2015156

The Recipes Table 1

MaterialsSelf Compacted Concrete 25/30

V1 V2

Cement, [kg] 420.00 460.00

Water, [kg] 171.00 171.00

W/C 0.45 0.45Sika Mixture ViscoCrete VF

2011, [kg] 2.50% 9.50 2.50% 9.50

Lime stone filler, [kg] 80.00 80.00

Total Aggregate, [kg] 1712.16 1712.16

0-4, [kg] 50% 856.08 50% 856.08

4-8, [kg] 13% 222.58 13% 222.58

8-16, [kg] 37% 633.49 37% 633.49

16-32, [kg] 0 0.00 0 0.00

The difference that adding less than 10%of cement can make in the compressionstrength of the self compacting concrete is

significant, as we can see in table Tab.2. InFig. 8 the L-box test is illustrated.

Fig. 7. Spread after preparation

Fig. 7 illustrates the uniformity of thespread of concrete mass. The overallspread was in each case 80 cm.

Fig. 8. L box after preparation

The concrete poured through the rebarwith no problem, and had the same heightat both ends.

O. Susa et al.: Self-Compacting Concrete used for building a monument with basic… 157

Experimental results Table 2

Determination type: Characteristics:Batch:

V1 V2

Determinations on freshconcrete

Excess water 1.714 0W/C real 0.305 0.372Density 2390 2316Spread (cm) 80 80L box 9 8V Funnel (sec) 32 18

Determinations on freshconcrete – at 60 min

Spread (cm) 80 0L box 0 (OK) 0V Funnel (sec) 32 0

Characteristics on 2 day onhardened concrete

Mass 7.90 7.60fc medium (N/mm²) 30.49 27.63fc minim (N/mm²) 29.60 25.87Density (kg/m³) 2341 2252

Characteristics on 28 dayhardened concrete

Mass 8.10 7.90fc medium (N/mm²) 57.72 44.95fc minim (N/mm²) 54.68 42.03Density (kg/m³) 2400 2341

Fig. 9 depicts the V funnel test-representing the cohesion of the concretemass, due to the fact that it had notsegregated and the flow of concrete wasconstant.

Fig. 9. V-furrnel

In Fig.10 we can see the resulted testcubes of the two recipes and the uniform

characteristics of both. There are no visualdefects of the resulting blocks of concrete

made out of the two self-compacting recipe

Fig. 10. Tested cubes

Curing conditions: the cubes of 15x15x15cm were kept in water for 28 days and testedby compressing them in order to determinethe compression strength- as depicted inFig. 11.

Bulletin of the Transilvania University of Brasov • Vol. 8 (57) Special Issue No.1 - 2015158

Fig. 11. Compresion Strengthdetermination

3. Conclusions

The experimental researches lead toobtaining a performing self-compactingconcrete realized with site ordinaryequipments. The all properties of fresh selfcompacting concrete were achieved incondition to use ordinary site concreteequipment.

The compressive strength after 28 dayswas around 57 N/mmm2 for V1 batch.

The V1 batch will be used to realize aconcrete monument exposed into a villagesquare.

References

1. Burak Felekoğlu et. al. The effect of flyash and limestone fillers on the viscosity

and compressive strength of self-compacting repair mortars, Cement andConcrete Research 36 (2006) 1719–17262. Mustafa Sahmaran, Heru AriChristianto, The effect of chemicaladmixtures and mineral additives on theproperties of self-compacting mortars,Cement & Concrete Composites 28 (2006)432–440.3.H.A.F. Dehwah, Mechanical propertiesof self-compacting concrete incorporatingquarry dust, powder, silica fume or fly ash,Construction and Building Materials 26(2012) 547–551.4. Syed Ali Rizwan, Thomas A. Bier,Blends of limestone powder and fly-ashenhance the response of self-compactingmortars, Construction and BuildingMaterials 27 (2012) 398–405. Heba A. Mohamed, Effect of fly ashand silica fume on compressive strength ofself-compacting concrete under differentcuring conditions, Ain Shams EngineeringJournal (2011) 2, 79–86.6. L. D’Aloia Schwartzentruber et. al.,Rheological behaviour of fresh cementpastes formulated from a Self CompactingConcrete (SCC), Cement and ConcreteResearch 36 (2006) 1203 – 1213.7. Burak Felekoğlu, Kamile Tosun, et al.,The effect of fly ash and limestone fillerson the viscosity and compressive strengthof self-compacting repair mortars, Cementand Concrete Research 36 (2006) 1719–1726.