The major purpose of this research is study the consequence of the type of lightweight sum ( Porcelinite and Thermostone ) , type and ratio of the pozzolanic stuff ( SF and HRM ) and the usage of different ratios of w/cm ratio ( 0.32 and 0.35 ) on the belongingss of SCLWC in the fresh and hard-boiled province. SF and HRM are used in three per centum 5 % ,10 % , and 15 % as a partial replacing by weight of cement for all types of SCLWC. The demands of self-compatibility for SCC are fulfilled by utilizing the high public presentation superplasticizer ( G51 ) at 1.2liter per 100 kilogram of cement.
The values of air dry denseness and compressive strength at age of 28 yearss within the bounds of structural lightweight concrete. The air dry denseness and compressive strength at age of 28 yearss for w/cm ratio ( 0.32 ) for SCLWC of Porcelinit sum are 1964 kg/m3 and 29.57 MPa, severally.
The corresponding values for the SCLWC of Thermostone sum are 1820 kg/m3 and 25.75 MPa, severally. The consequences show that the HRM public presentation which is locally available is better than SF in production of SCLWC.
Lightweight concrete ( LWC ) is a concrete which by one agencies or another has been made lighter than conventional concrete. Using concrete with a lower denseness can, hence, consequence in important benefits in footings of supporting elements of smaller cross-section and a corresponding decrease in the size of foundations. Furthermore, with lighter concrete, the formwork needs to defy lower force per unit area than would be the instance with normal weight concrete, and besides the entire mass of stuff to be handled is reduced with a attendant addition in productiveness. Concrete which has a lower denseness besides gives better thermic insularity than ordinary concrete and possesses good fire and hoar opposition ( Neville 2005 ) . Self-compacting concrete ( SCC ) represents one of the most outstanding progresss in concrete engineering during the last decennary. Due to its specific belongingss, SCC can lend significantly to the quality of concrete constructions and open up new Fieldss for the applications of concrete. SCC describes a concrete with the ability to pack itself merely by agencies of its ain weight without the demand of quiver, it fills all deferrals, support infinites and nothingnesss even in extremely strengthened concrete members and flows free of segregation about to a flat balance. Self-compacting lightweight concrete is a new edifice stuff which combines the known advantages of lightweight concrete and self-compacting concrete. Lightweight concrete with self-compacting ability offers considerable benefits, from cut downing the denseness of concrete and supplying self-compacting belongingss.
The workability of self-compacting lightweight concrete ( SCLWC ) can be characterized by the undermentioned belongingss ( Badman 2003 )
1. Filling ability: the ability of SCLWC to flux under its ain weight ( without quiver ) to make full wholly all infinites within intricate formwork, incorporating obstructions, such as support.
2. Passing ability: the ability of SCLWC to flux through gaps nearing the size of the mix coarse sum. such as the infinites between steel, reenforcing bars, without segregation or sum blocking. This belongings is of concern in those application that involve arrangement in complex forms or subdivisions with closely separated support.
3. Segregation opposition ( stableness ) : the ability of SCLWC to stay homogeneous during transit, placing and after arrangement.
1-1 Development of Self-Compacting Concrete
For several old ages get downing in 1983, the job of the lastingness of concrete constructions was a major subject of involvement. To do lasting concrete constructions, sufficient compression by skilled workers is required. However, the gradual decrease in the figure of skilled workers in building industry has led to a similar decrease in the quality of building work. One solution for the accomplishment of lasting concrete constructions, independent of the quality of building work, is the usage of self-compacting concrete, which can be compacted into every corner of a formwork, strictly by agencies of its ain weight and without the demand for vibrating compression ( Ouchi 1999 ) .
. 1-3 The methods for achievement self-compatibility
Okamura and ouchi ( 2003 ) have employed the following methods to accomplish self-compatibility:
1-limited sum content ;
2- low water-powder ratio ;
3- Use of superplastizer.
They found besides that the extremely syrupy paste is besides required to avoid the obstruction of coarse sum when concrete flows through obstructions, Fig. ( 2-4 ) .When concrete is deformed, the paste with a high viscousness besides prevents localised addition in internal emphasis due to the attack of harsh sum atoms. High deformability can be achieved by the employment of a superplasticizer, maintaining the water-powder ratio to a really low value. They have besides found that the frequence of hit and contact between aggregative atoms can increase as the comparative distance between the atoms lessenings and so internal emphasis can increase when concrete is deformed, peculiarly near obstructions. They have concluded that the energy required for fluxing is consumed by the increased internal emphasis, ensuing in obstruction of aggregative atoms. Restricting the harsh sum content to a degree lower than normal, which is effectual in avoiding this sort of obstruction.
Structural ligthweigth concrete ( SLWC )
The ( American Concrete Institute ) ( ACI 213R-91 ) defines the structural lightweight concrete as a concrete which ( a ) : has a minimal compressive strength at 28 yearss of 17.2MPa, ( B ) : has a corresponding air-dry unit weight in a scope of 1440 to 1850 kg/m3 and ( degree Celsius ) : consists of all lightweight sum LWA or a combination of LWA and normal weight sums.
Al-Rawi ( 1995 ) has studied the belongingss of Porcelinite lightweight sum to bring forth LWC. 18 mixes in assorted mix proportion are prepared without utilizing any alloy. Cement content was between 272 – 687kg/m3 and water/cement ratios ranged between 0.65-1.6.The lightweight concrete used in this probe can offer a compressive strength up to 32MPa with an air dry denseness of 1815 kg/m3 at 28 yearss.
1-5 Self-Compacting Lightweight Concrete ( SCLWC )
Self-compacting lightweight concrete ( SCLWC ) is a new high-performance edifice stuff, which combines the well-known advantages of lightweight concrete with those of self-compacting concrete ( SCC ) .
Kobayashi ( 2001 ) has examined the features of SCC in fresh province with unreal lightweight sum ( LWA ) .Whereas, the unreal LWA has lower H2O soaking up ratio than ordinary LWA because of its tight surface construction, and can be used for concrete blending without pre-wetting process. Another advantage of this sum is its spherical form that is expected to increase fluidness of concrete. The consequences show that SCC with this sum has higher self-compactability than that with crushed rock, while the distortion rate of concrete is really little. Segregation between the sum and howitzer, nevertheless, tends to be big because of larger difference of specific gravitation between them than in the instance of ordinary self-compacting concrete with crushed rock. Increase in unit mass of the lightweight sum does non impact so much on self-compactability of concrete.
2- Objective of the research
The chief aim of this survey is to look into the consequence of the undermentioned variables on the belongingss of SCLWC in the fresh and hard-boiled provinces:
1. type of lightweight sum by utilizing porcelinite and waste crushed Thermostone sum.
2. type of mineral alloies by utilizing silica smoke ( SF ) and high responsiveness metakaoline ( HRM ) .
3. Water cement ratio by utilizing two values of 0.32 and 0.35.
Consequences of this research will supply information about the rheological and mechanical belongingss of self-compacting lightweight concrete. High public presentation superplasticizer ( Glinume 51 ) is used as chemical alloy in this survey. In this survey, the self-compatibility trials ( Slump flow, V-Funnel, L-Box, U-Box ) were performed on the fresh concrete for each mix of SCLWC. Air dry denseness at 28 yearss, compressive strength and splitting tensile strength at 7,28,90 twenty-four hours trials are conducted. 28 concrete mixes are investigated in fresh and hard-boiled province. A sum of 252 concrete regular hexahedrons of 150 millimeters, 252 concrete cylinders of 150A-300 millimeter, are cast, cured and tested for this survey.
3- Experimental work
AL-Shemalia ordinary Portland cement manufactured in Kingdom of Saudi Arabi ( KSA ) is used in this research. the consequences of the chemical analysis and physical belongingss of the cement indicate that the available cement is conformed to the Iraqi Specification as shown in Table 1.
drinkable H2O is used as a commixture H2O for all concrete mixes.
Al-Ekhaider sand of 4.75 millimeters maximal size is used as all right sum in concrete mixes the consequences of the chemical analysis and physical belongingss of the sand indicate that the available sand is conformed to the Iraqi Specification as shown in Table 2.
Crushed rock Porcelinite has been used as harsh sum in this survey with soap. size 9.5 millimeter
Thermostone sum is considered as one of the industrial remainder which is accumulated during industrial procedure of Thermoston blocks. it used with soap. size 9.5 millimeter.
The scaling and physical belongingss of Porcelinite and Thermostone aggregate conform to the demands of the ASTM C330 as shown in Fig. 1 and Table 3 severally.
A high public presentation concrete superplasticizer Glinume 51 ( G51 ) is used in this research as chemical alloy.G51 complies with ASTM C494 Types A and F
Silica smoke ( SF )
The chemical analysis of SF was used in this research conforms to the chemical demands of ASTM C1240 as shown in Table4 and Table 5.
High Reactivity Metakaoline ( HRM )
The chemical analysis of HRM was used in this research conforms to the chemical demands of ASTM C618 severally as shown in Table 6 and Table 7.
Design of Concrete Mixes
The design of SCLWC mixes is performed to bring forth structural lightweight concrete conforms to the demands of structural LWC, harmonizing to ACI Committee 213 In the same clip, the mix deign of SCLWC must fulfill the standards of make fulling ability, go throughing ability and segregation opposition. The mix design method of SCC used in the present survey is harmonizing to EFNARC 2005, Two series are used throughout this research, Porcilinite sum is used as a harsh sum in the first series, Thermostone sum is used as a harsh sum in the 2nd series. Two w/c ratios ( 0.32 and 0.35 ) are adjusted for each mix and The optimal dose of GLINUME51 ( G51 ) ( 1.2 litre per 100 kilogram of cement ) For all mixes, cement content is 500 kg/m3, all right sum is 590 kg/m3 and harsh sum is 620 kg/m3.
3-5 Mixing of concrete
The Porcelinite and Therrmostone sum is used in concentrated surface prohibitionist ( SSD ) , which is recommended by the ACI commission 211-2. In this survey the method of Emborg2000 is used in the commixture of mention concrete ( LWC ) and self-compacting lightweight concrete. This method includes the undermentioned stairss for mention concrete:
1.The dry measure of all right sum is assorted with 1/3 of blending H2O for 1 minute.
2.The measure of cement with 1/3 of blending H2O is added to the mix and the mixture is assorted for approximately 1 minute.
3.The measure of harsh aggregative plus 1/3 of blending water+1/3 of the dose of the alloy are added to the mix and the mixture is assorted for approximately 1 minute after that leave the mixture to rest for 1.5 minute.
4. The remained dose of the alloy is added to the mix and the mixture is assorted for approximately 1.5 minute.
For blending the SCLWC the same stairss as shown above except before adding the measure required of cement, the needed measure of mineral alloy ( S.F or HRM ) is added by the weight of cement and assorted with the cement merely for approximately 15 2nd to scatter all the atoms of mineral alloy ( S.F or HRM ) throughout the cement grains.
Testing of concrete
Testing of Fresh Concrete
Slump trial was used to find the workability for mention concrete. This trial is performed harmonizing to ASTM C143.
Slump Flow Test, V-Funnel trial, L-Box Test and U-Box Test were used to qualify the belongingss of SCLWC ( make fulling ability, go throughing ability and segregation opposition these trials were performed harmonizing to EFNARC 2002 and EFNARC 2005.
Testing of Hardened Concrete
Compressive Strength: The compressive strength trial is carried out on 150mm regular hexahedrons This trial was performed harmonizing to BS1881: portion 116 The specimens are tested at ages of 7,28 and 90 yearss and in each age the norm of three specimens are adopted.
Dividing Tensile Strength: The dividing tensile strength trial is performed harmonizing to ASTM C496,150A-300 millimeter cylindrical concrete specimens are used. The specimens are tested at age of 7,28 and 90 yearss and in each age the norm of three specimens has been adopted
Hardened Unit Weight ( 28 Days Air Dry Density ) : This trial is used to find the air dry denseness of concrete mixes Cubes specimens of 150mm are used in this trial at age of 28 yearss the trial is performed harmonizing to ASTM C567.
4- Properties of Fresh SCLWC
Slump Flow: The consequences of Slump flow trial ranged between 657- 712 millimeter for SCLWC mixes produced from Porcelinite sum and scope between 679 — 769 millimeter for SCLWC mixes produced from Thermostone sum. These consequences are within the acceptable standards for SCC and indicate besides first-class deformability and make fulling ability without any segregation, shed blooding and barricading.
V-Funnel: The consequences of V-Funnel trial ( flow clip ) for SCLWC mixes produced from Porcelinite sum scope between 6.4-12.4sec. and for SCLWC mixes produced from Thermostone sum scope between and 6-11.5 sec for. These consequences are within the acceptable standards for SCC.
L-Box: The consequences of L-Box trial barricading ratio ( H2/H1 ) scope between 0.8-0.94 for all mixes of SCLWC. These consequences are within the acceptable standards for SCC and indicate that the mixes have first-class passing ability.
U-Box: The consequences of U-Box trial filling tallness ( H1aa‚¬ ” H2 ) scope between 12-28 millimeter for all mixes of SCLWC. These consequences are within the acceptable standards for SCC.
5- Hardened Concrete Properties
Compressive Strength: The consequences of compressive strength trial for all concrete mix in this survey at 28 yearss are higher than 17 MPa, the lower limit needed strength recommended by ACI-213 for structural LWC.
At early ages ( 7 yearss ) ( see Fig2 ) for the same w/cm ratio the compressive strength for all concrete mix of SCLWC incorporating SF is higher than concrete mix of SCLWC incorporating HRM and mention mix The part of silica smoke to the early strength development ( up to 7 yearss ) is done betterment in wadding and the interface zone with sum ( Neville 2002 ) While for HRM, the dilution consequence of it, when is used as a partial replacing for cement. The concrete mixture will besides see some consequence of the remotion of cement from responding system and that impacting the early compressive strength ( Justice 2005 ) For this ground, all concrete mixes of SCLWC incorporating HRM give compressive strength at 7days less than the compressive strength of mention concrete at the same age. At 28 and 90 yearss ( see Figs. 2 ) for the same w/cm ratio the compressive strength for all concrete mixes of SCLWC incorporating HRM was higher than concrete mix of SCLWC incorporating SF. This is due to high pozzolanic activity of HRM if compared with SF ( P.A.I for SF=108 % , for HRM=140 % ) as HRM the major constituents responsible for the pozzolanic reaction are alumina and silicon oxide ( Advanced Cement Technology 2002 ) From the chemical composing of HRM used in this survey, the sum per centum of aluminum oxide ( AL203 ) and silicon oxide ( SIO2 ) is 91.17 % , more than the per centum of formless silicon oxide ( SIO2 ) in SF which is responsible for the pozzolanic reaction ( ACI234R-96 ) ( SIO2=87.45 % for SF used in this survey ) . The pozzolanic reaction take topographic point between the constituents mentioned above in pozzolanic stuff ( SF and HRM ) and calcium hydrated oxide CH formed during the hydration procedure. This leads to the cementations compound which is produced from the reaction of HRM more than the cementations compound which is produced from the reaction of SF and this leads to compaction of the concrete matrix ensuing in a considerable addition in strength, and decrease in permeableness. Besides, the pore-size and grain-size polish procedures associated with pozzolanic reaction can efficaciously cut down the microcraking and beef up the passage zone ( Mehta et al 2006 ) .
Dividing Tensile Strength: Due to the use of mineral alloies ( SF and HRM ) , chemical alloies ( Glinume 51 ) , in add-on to the self- compactability, an betterment to the ITZ is expected. Consequently, good consequences of tensile strength are expected. Figs ( 3 ) show that at early ages ( 7 yearss ) and for the same w/cm ratio dividing tensile strength of SCLWC mixes incorporating SF is higher than SCLWC mixes incorporating HRM and mention mixes. This is due to the physical consequence of silicon oxide smoke and the ability of the highly all right atoms of silicon oxide smoke to be located in really close propinquity to the sum atoms, that is, at the aggregate-cement paste interface, and this allows to the cement particles packing tightly against the surface of the sum, and this leads to beef up the ITZ. A conducive factor is the fact that silicon oxide smoke because of its high choiceness, reduces shed blooding so that no bleed H2O is trapped beneath harsh sum atoms. Consequently, the porousness in the ITZ is reduced so dividing tensile strength increased ( Neville 2002 ) . Due to the dilution consequence of HRM when it is used as a partial replacing of cement, dividing tensile strength at 7 yearss of SCLWC mixes incorporating HRM is less than mention mixes ( LWC ) . At 28,90 yearss and for the same w/cm ratio Figs ( 3 ) show that the splitting tensile strength of SCLWC mixes incorporating HRM is more than SCLWC mixes incorporating SF, this because of high pozzolanic activity of HRM if compared with SF as shown in pervious subdivision. The pozzolanic reaction strengthen the passage zone through procedures of pore size and grain size polish, therefore cut downing the microcracking of concrete. in add-on the well and unvarying scattering of cement and atoms of mineral alloy ( HRM and SF ) by the action of superplasticizer ( Glinume 51 ) leads to a great betterment in tensile strength ( Mehta et al 2006 ) ( Druta 2003 ) .
Hardened Unit Weight ( 28 twenty-four hours air dry denseness ) : The consequences show that the 28 yearss air dry denseness for concrete mixes produced from Thermostone sum conform to the demand of ACI 213 for structural LWC. The 28 yearss air dry densenesss for concrete mixes produced from Porcelinite sum more than 1850 kg/m3, but they are below 2000 kg/m3. However all concrete mixes in this survey conform to the demand of structural lightweight sum concrete, harmonizing to British specification which limits the maximal denseness of structural lightweight concrete to 2000 kg/m3.
The 28 yearss air dry densenesss for SCLWC mixes incorporating HRM more than SCLWC mixes incorporating SF ( see Fig. ( 4 ) ) . This is due to the extremely pozzolanic activity of HRM if compared with SF. The Cementation compound that consequences from the pozzolanic reaction of HRM is more than the cementation compound that consequence from pozzolanic reaction of SF, and this leads to an addition in cement gel and denseness.
From Fig. ( 4 ) . The consequences show that the 28 yearss air dry densenesss of all SCLWC mixes are more than mention concrete mixes ( LWC ) , this behaviour can be ascribed to the pozzolanic reaction of mineral alloy ( HRM and SF ) in SCLWC mixes. The pozzolanic reaction leads to an addition in cement gel ( the cementation compounds ) , it besides leads to the compaction of concrete matrix and the passage zone through the procedures of pore-size and grain-size polish ( Mehta et al 2006 ) .
It is possible to bring forth SCLWC by utilizing two types of locally available porcelinite or thermostone as harsh lightweight sum, high public presentation superplasticizer ( Glinume51 ) and extremely active pozzolanice stuffs ( HRM and SF ) .
Consequences of this probe indicated that locally available HRM performs better than SF in produced SCLWC.
The SCLWC mixes produced from Porcelinite sum showed considerable betterment in all mechanical belongingss compared with SCLWC mixes produced from Thermostone sum.
at 28 yearss There is a positive relationship between the air dry denseness and compressive strength and the per centum of the added pozzolanic stuff and the compressive strength of the SCLWC mixes.
There is no important addition in all mechanical belongingss of SCLWC mixes for w/cm ratio 0.32 if compared with SCLWC mixes for w/cm ratio 0.35.
There is no important addition in all mechanical belongingss of SCLWC mixes for w/cm ratio 0.32 if compared with SCLWC mixes for w/cm ratio 0.35.
The values of air dry denseness and compressive strength for SCLWC mixes produced from Thermostone sum at 28 yearss are within the demands bounds of structural LWC. At 28 yearss, the air dry denseness ranges between 1710-1820 kg/m3 and 1688 -1795 kg/m3 for w/cm ratio 0.32 and 0.35 severally. The compressive strength ranges between 20.14 -25.75 MPa and 19.89 -25.21 MPa w/cm ratio 0.32 and 0.35 severally. For mention concrete ( LWC ) the 28 yearss air dry denseness falls between 1683 and1653 kg/m3 and the compressive strength falls between 18.50 and 17.88 MPa for w/cm ratio 0.32 and 0.35 severally. the dividing tensile strength at 28 yearss ranges between 2.55 -3.09 MPa and 2.35 -2.89 MPa for w/cm ratio 0.32 and 0.35 severally. For mention concrete ( LWC ) , the splitting tensile strength at 28 yearss falls between 2.44 and 2.19 MPa for w/cm ratio 0.32 and 0.35 severally.
The values of air dry denseness and compressive strength for SCLWC mixes produced from Porcelinite sum at 28 yearss are within the demands bounds of structural LWC. At 28 yearss, the air dry denseness ranges between 1907-1964 kg/m3 and 1844-1944kg/m3 for w/cm ratio 0.32 and 0.35 severally. The compressive strength ranges between 24.12 -29.57 MPa and 22.22 -27.89 MPa w/cm ratio 0.32 and 0.35 severally. For mention concrete ( LWC ) the 28 yearss air dry denseness falls between 1890 and 1823 kg/m3, and compressive strength falls between 21.76 and 20.5 MPa for w/cm ratio 0.32 and 0.35 severally. The dividing tensile strength at 28 yearss ranges between 3.17 -3.77MPa and 2.84 -3.27 MPa for w/cm ratio 0.32 and 0.35 severally. For mention concrete ( LWC ) , the splitting tensile strength at 28 yearss falls between 2.91 and 2.69 for w/cm ratio 0.32 and 0.35 severally.