Kiln-Dust as Partial Replacement of Cement in Concrete

Transcription

1

2 Kiln-Dut a Partial Replacem of Cem in Concrete Adakole Edwin Agbo 1+ Calitu Ayegba 2 1.Departm of Building, Federal Univerity of Technology Minna Niger State, Nigeria 2. Departm of Building, Federal Univerity of Technology Minna Niger State, Nigeria Abtract Thi reearch invetigate the trength characteritic of concrete made with cem-kilndut with a view to determine the influence of replacing certain percage of ordinary Portland cem with kiln-dut in cem kiln-dut concrete. The reearch wa carried out in accordance with Britih tandard BS (812, 882, 1881 and 40). The kiln-dut wa mechanically grounded into powder with grinding machine and ieved with a tack of BS ieve. The powdered kiln-dut wa mixed with ordinary Portland cem in three differ proportion of 10%, 20% and 30% cont of kilndut which wa ued for experim. Two hundred and forty 100mmX100mm concrete cube were cated, cured and cruhed including the control pecimen to failure to determine the compreive trength. The reult of 28 th compreive trength for 10%, 20% and 30% of with kiln-dut were 27.N/mm 2, 26.66N/mm 2 and 26.7N/mm 2 repectively. The water cem ratio for the mix proportion wa 0.66, 0.7 and 0.87 for 10%, 20% and 30%. The reearch conclude that can be replaced with 10%, 20% and 30% of kiln-dut cont in concrete. Key word: Kiln-dut, Compreive trength, Concrete. 1. Introduction Mot developing countrie like Nigeria have been uffering from an acute hortage of contruction material, principally becaue of the ever increaing demand for new contruction work. The continuou demand for new contruction work ha triggered a continual increae in the cot of convional building material like cem. The contruction indutry depend heavily on cemeou material a binding ag in her operation to develop helter and road infratructural work. Many cemeou material ha been ued a binding ag in concrete, mortar and andcrete block but the mot commonly ued are cem and bitumen [2]. In Nigeria, cem i the generally ued binder for contruction work. Thu the demand for cem in Nigeria became higher than the upply and thi ha jacked up the price of cem beyond the level that an average income earner in Nigeria can afford [3]. Thi ituation ha neceitated the developm of alternative and cheaper material like kiln-dut, Ricehuk, Groundnut hell ah and other pozzolana to mion a few to replace cem in concrete, mortar and andcrete block [ & 3]. The idea of uing wate material like Kiln-dut, ricehuk and groundnut hell ah a an alternative to cem have long been experimed. Apart from aving the cot of dipoal, their ue in contruction protect the environm from pollution which could be harmful to human life [4 & 1]. Kiln-dut ometime known a precipitator dut i produced abundantly during the production proce of ordinary Portland cem (). The dut i a wate product. It chemical and phyical compoition varie from plant to plant. Thee variation are due to the variation in the raw material ued, location and type of collection ued [1]. The behavior of the kiln-dut generally governed the choice of collection of the material for any contruction work [1]. Thi reearch work wa primarily informed a a reult of force of demand in the convional cem which triggered the price of Portland cem in Nigeria beyond the reach of an average income earner in Nigeria. The knowledge of the practical uefulne of the kiln-dut will go a long way to benefit contractor, reearcher a well a the ociety at large. However, the fundamal quetion to be ak here i, uppoe local wate material like kiln-dut wa ued a a partial of cem in concrete for contruction, could it have performed 437

3 better than convional cem in term of trength, durability and cot wie? Thi reearch i aimed at providing an anwer to thi quetion. The pecific objective of thi reearch include 1. To determine the phyical and chemical compoition of the kiln- dut 2. To determine the influence of kiln-dut on the trength characteritic of the cem kiln-dut concrete 3. To determine the required percage cont of ordinary Portland cem() that can be replace with kiln-dut in cem-kiln- dut concrete for high trength concrete. 4. To achieve thee et objective, erie of experim where carried out a decribed in the next ection. 2. Material and Method 2.1 Material Collection A number of material where collected and ued in the coure of thi tudy. The material include: kilndut, fine aggregate (and), coare aggregate (cruhed toned), ordinary Portland cem () and water. The kiln-dut wa obtained from dangote cem in gboko, formal benue cem company (BCC). The fine and coare aggregate where obtain from flooded pit and river in jo where the reearch wa conducted. 2.2 Experimal Procedure The experim carried out for thi reearch where group into two, the preliminary experim and the main experim Preliminary experim The quantity of the kiln-dut collected wa grounded mechanically into powdered from uing grinding machine. The powder wa ieve through a tack of BS ieve ize 300um, 10um, and 7um uing mechanical ieve haker to hake for minute. Only powdered particle that pa through the 7um tandard BS ieve (No 200) wa collected and ued for thi experim. The fine aggregate wa natural and from flooded pit which wa of grading zone 1 of [7 & 8]. The coare aggregate (cruhed tone) wa graded a atifie [7] requirem for concrete graded coare aggregate. Other preliminarie and tet carried out include: appar pecific gravity of the kiln-dut, bulk denity tet, water aborption tet, etting time tet and chemical compoition tet a contained in the tet reult bellow Main/major experim For the purpoe of thi reearch, three mix proportion of cem-kiln-dut concrete with 10%, 20% and 30% cont of powdered kiln-dut were ued for the experim. From the water aborption tet, the appropriate water cem ratio wa decided for each mix proportion. The material (gravel, and, cem, kiln-dut and water) were mixed together manually between five to ten minute (-10 min) for each mix proportion and a uniform mix wa achieved. Slump tet for all the mix proportion were carried out according to [6]. A total of 240 cube were cated for the three differ mix proportion (10%, 20% and 30%) and for the control pecimen. The pecimen were cat in 100mm x 100mm teel cube mould at ambi average room temperature of 32 o C which i higher than recommended temperature of o C by the [13]. All the pecimen in the cube were compacted according to [9]. After 24hour, the mould wa removed from the pecimen, and the pecimen are cured in a curing tank uing ordinary tap water in accordance with [8]. The curing wa done for 7, 14, 21, 28, and 90. At the end of each curing period, 1 cube for each mixed proportion including the control mix will be removed from the curing tank and cruhed manually to determine their compreive trength. Detail of the reult are hown on the next ection. 438

4 Table 1.0 Quantity of material in (kg) per cubic meter. 3. Reult and Dicuion Thi ection pre the reult of both preliminary tet and the main tet carried out in thi reearch in a tabular form. The reult of each the main tet i preed in a eparate table and dicued accordingly. Property Appar pecific gravity Sieve analyi Finne modulu Looe bulk denity Compacte d bulk denity Water aborbtion Initial etting time Final etting time Table 2.1 Phyical Propertie of Material. mater Control 10% 20% 30% ial mix 0% Sand Grave l Water Ceme nt Kilndut Kilndut Sand (from floode d pit) Gravel Cemen t Zone 1 Size - 20mm kg/m kg/m 3 40% hr 38mi n 8hr 6mi n - - 1hr 12min - - 4hr 38min - - Table 2.2 Chemical compoition Kiln-dut Percage pre Cem Percage pre CaO 4.63 CaO 61.0 SiO SiO Al 2 O 3.14 Al 2 O Fe 2 O Fe 2 O MgO 2.64 MgO 1.61 SO SO NaO 0.43 NaO 0. K 2 O 0.38 K 2 O 0.32 Lo in ignition Source (field data) Soroka (1979) The ummary of the reult in table 2a and 2b of the tet carried out indicate compliance with tandard of [7] for ieve analyi of fine and coare aggregate. The pecific gravity and water aborption atify [7 & 12]. The initial and final etting time of the kilndut wa long but till within the tipulation of BS812. The bulk denity (looe and compacted) of 1337kg/m 3 and 1413kg/m 3 indicate that the granite ued for the experim i of heavy weight ince thi value fall outide the value of 300 to 1200kg/m 3 pecified by [7] for light weight aggregate. The chemical compoition how that the percage of Cao, Sio3and Al 2 O 3 pre wa up to 70% indicating the kiln-dut can be ued a cemeou material to partially replace cem in contruction work. Table 3. Workability tet Kiln-dut cont Slump Compaction factor (%) (mm) 10% % % The reult of the lump tet and compaction factor hown above on freh concrete indicated concrete ranging from low to high workability. Thi reult wa within the pecification of [6]. 439

5 w/ c rat io Table 4. Variation with Age of Compreive Strength Cont rol mix %of repla ced with kiln dut Compreive trength (N/mm 2 ) The reult of compreive trength hown in table 4 reveal that at 28 and 90 of age, 0% (100% ordinary Portland cem) gave the highet value of compreive trength of (30.8N/mm 2 and 31.0N/mm 2 ) among all the mix proportion, but the trength decreae with an increae in the percage of by kilndut. For intance the 7 th trength of 10% with kiln-dut wa 8% of the 0% and the 28 th trength of 10% with kiln-dut wa 84% of 0%. It wa oberved that in all the mix proportion, only the mix with 10% attained 60% of it 28 trength at 7. According to [13] concrete i expected to attain 60% of it 28 compreive trength at 7. However, all the mix proportion (10%, 20% and 30% ) attained their expected compreive trength at 28. Similarly, there wa a ubtantial difference between the 7 th and 28 th compreive trength for all the mix proportion. Thi wa likely due to increae in hydration of the kilndut which normally occur at a later age. Thi tatem can be confirmed from the etting time period in table 29. With increae in age, more calcium hydroxide (a byproduct of ordinary Portland cem hydration) i utilized by kiln-dut to produce more binding material which will ubequly lead to more trength of the concrete [11]. It wa alo noticed that a the percage of the ordinary Portland cem being replaced increae (i.e. a the kiln-dut cont increae) the 28 th and 90 th compreive trength of the concrete decreae. Though for concrete grade C2, C30 repectively for all the mix, it wa oberved that the highet trength obtained on 28 th wa 27.0N/mm 2 which wa from 10% and the lowet wa 26.27N/mm 2 which wa from 30% with kiln-dut. The rate of trength gain with age of the concrete i hown in table 6. W/ C rati o Table 6: Rate of Strength Gained with Age. a contr ol mix 100% % of Age (in ) replace d with kilndut From the table 6 above, the control mix (100% ) and 10% with kiln-dut indicate that the rate of trength gain decreae a the age of the concrete increae while 20% and 30% with kiln-dut have no particular pattern. 440

6 Fig 1. Variation in Compreive Strength of Concrete with Age for the control mix and the ire % Replacem. 4. Concluion Baed on the reult of the tet carried out on the compreive trength of the cem-kiln-dut concrete and the preliminary tet carried out on the following concluion were drawn Ordinary Portland cem can be replaced with 10%, 20% and 30% with kiln-dut in concrete and till perform well a 0% (100% cem). The kiln-dut required high water cem ratio and longer period of etting time a compared to convional The compreive trength of cem kilndut concrete decreae with increae in the percage cont of the kiln-dut The highet compreive trength (28.62N/mm 2 ) wa obtained from 10% of with kiln-dut at 90 of age.. Recommendation Baed on the finding of thi reearch work, it i recommended that further reearche be carried out to etablih the maximum percage of that can be replaced with kiln-dut in concrete. It i alo recommended t hat imilar reearch hould be carried out in mortar. 6. Reference [1]. Baghdadi, Z.A, Rhman, M.A (1990) Potial of Cem-Kiln-dut for tabilization of dun and in highway contruction. Building and Environm vol. 2,No4, pp [2]. Neville, A.M, Brook, J.J (2002) Concrete technology, 2 nd edition Pearon Education Ltd New Delhi. Pp10-33, [3]. Dahan, I.I, Nwankwo, P.O (2000) The behavior of palm kernel hell concrete at elevated temperature. Nigerian Journal of Contruction Technology and Managem.vol3 No1 pp47-2. [4]. Ramakrihnan,V.(1986) Evolution of kiln-dut in concrete proceeding on fly ah, ilica, fume lag and natural pozzolan in concrete. 2nd international conference, Madrid Spain. Vol. 1 pp []. Job, F.O.(1998) Concrete made with Pulverized Burnt Clay a Partial Replacem of Cem. Nigerian Journal of Contruction Technology and Managem.vol 1 no1 pp [6]. Britih Standard Intitution (197,1978) BS 812: Method of ampling and teting of material/aggregate. Britih intitution of London 441

7 [7]. Britih Standard Intitution (1983) BS 882: Part 2: Aggregate from natural ource for concrete: Britih Standard Intitution London [8]. Britih tandard intitution (1983) BS 1881, part 3: method of normal curing of tet pecimen Britih tandard intitution London [9]. Britih tandard intitution (1983) BS 1881, Part 102, 103 and 166: Method of determine compreive trength, compaction factor and lump. Britih Standard Intitution London. [10]. Britih Standard Intitution (1970) BS 40; Part 2; Chemical tet for cem. Britih Standard Intitution London [11]. Saad, M.M; Garba M.M; Okoli, O.G. (2007) comparative trength of pozzolana-portland cem mortar. Nigeria journal of contruction technology and managem vol. 8 No 1 pp [12]. ASTMC Tet for finne of Portland cem by turbid meter. [13]. Neville, A.M. (1981) propertie of concrete 3 rd Edn. London Pitman Publihing Company Ltd. 442