BY DUNA SAMSON MATAWAL D.S EJEH S.P A PAPER PRESENTED AT NIGERIAN BUILDING AND ROAD RESEARCH INSTITUTE CONFERENCE ON 2nd TO 4th JUNE, 2014 PRESENTATION OUTLINE INTRODUCTION LITERATURE REVIEW MATERIALS AND METHODS RESULTS DISCUSSION OF RESULTS CONCLUSION AND RECOMMENDATION 1.0 INTRODUCTION 1.1 Background of Study Nigeria is a developing country with an estimated population of 170 million. The country is faced with many Infrastructural problems such as Inadequate Infrastructure For these infrastructure to be developed, it requires the use of cement and other construction materials. The high and increasing cost of cement has contributed to the non-realization of these infrastructures. Background of Study Continues For example, from June 2003 to June 2005, the price of 50kg of cement rises from N730 to N1600, an inflation of 119% in 2 years. While in 1984 the same bag cost N5.00 an inflation of 31,900% in 21 years. Background of Study Continues Background of Study Continues Part of the solution to the high cost of cement is the use of supplementary cementing material (SCM). This study was geared towards finding alternative and relatively cheap materials for use as substitute for Ordinary Portland Cement in the production of Sandcrete hollow blocks. Fly Ash (FA) was used as cement replacement in the study Background of Study Continues 1.2 Aim of Study The aim ofstudy is to produce hollow Sandcrete blocks using fly ash (FA) as cement replacements, the study also has the following objectives. (a)Determine the composition of the ash (FA) and to establish whether they can be used as Pozzolana. (b) Determine the optimum percentage of ash to be used as partial replacement of cement in the production of sandcrete hollow blocks.(c)Evaluate the Engineering properties of the hollow sandcrete blocks made with the ash at the various percentages ofcement replacements. Objective of Study Continues 1.3 Statement of Research Problem The problems to be addressed by this study are: Over dependency on cement. High level of pollution. Emission of green gases (CO2) Depletion of natural resources. 2.1 Fly Ash (FA) Fly ash (Pulverized fuel Ash) is finely divided residue resulting from the Combustion of coal or powered coal. Nigeria is estimated to have a coal deposit of about 1.54 trillion tonnes Ugwu (1996). The use of coal in Nigeria has reduced as compared to its use in the sixties, due to the discovery of oil. 2.0 LITERATURE REVIEW Recent development in Nigeria has shown that the era of coal will soon be visited.The ash resulting from the plant, being a waste if not utilized will results in environmental Pollution. Fly Ash Continues Dunstan (1984), Hang and Lee (1989) equally reported that fly ash concrete have high sulphate resistance and can be used to improve water tightness, when used in water retaining structures. Fly Ash Continues BS 3892 (1965) recommends a maximum of 35% by weight of the pozzolana in Portland cement. Ogalla (2004) studied the performance of fly ash in concrete and concluded that cement can be replaced with the ash at 20% replacement. Fly Ash Continues 3.0 MATERIALS AND METHODS The materials used for the study are CementFine aggregate(Sand) WaterFly ash (FA) Materials and Methods Cont. 3.1 Cement Ashaka brand of Portland cement was used. The Cement was procured from a reputable dealer in Yelwa market, bauchi The fine aggregate(sharp Sand) used was obtained from a stream in Bayara along Bauchi Dass road in Bauchi. The test conducted on the fine aggregate were Particle size distribution Silt Content 3.2 Fine Aggregate (Sand) Portable clean water from tap fit for drinking was used throughout the experimental work No test was necessary on the water, as it is portable. 3.3 Water The fly ash (FA) used for this study, was procured from Ashaka Cement Factory Gombe.The fly ash is the waste resulting from the combustion of coal used for burning limestone and other raw materials.3.4 Fly Ash 3.4.1 Production of fly Ash (FA) The physical and chemical analysis of FA was carried out in line with the standard procedure. at the National Metallurgical Development Centre Jos, Plateau State, Nigeria. 3.5 Physical and Chemical Analysis of FAIn order to ascertain the suitability of the ashes. Their individual pozzolanic activity index were determined using equa. 1. 3.6 Determination of Pozzolanic Activity Index (PAI) Determination of Pozzolanic Activity Index (PAI) Cont. ------1 Compressive strength at 28 days test specimen Compressive strength ofthe control specimen at 28 days PAI =Cement paste were made with various quantities of FA as cement replacements. The percentage replacements were made at 0, 5, 10, 20, 30, 35, 40 and 50%. 3.7 Effect of FA on Cement The test conducted on the cement paste were Consistency Setting times andSoundness Effect of FA on Cement Cont. The FA were collected, broken into smaller sizes, and grounded using mortar and pestle. The ash was sieved using sieve size 212m The quantities of the ash passing sieve size 212m was used to produce the blocks. 3.8 Production of Sandcrete Hollow Blocks Sandcrete mixes 1 part of Cement to 6 parts of Sand(1:6) and 1 part of cement to eight part of sand (1:8) ratio were used. A water cement ratio of 0.6 was adopted in all the mixes as recommended by Okpala and Ihaza (1987). Production of Sandcrete hollow blocks Continues For each mix proportion 0, 5, 10, 20, 30, 35, 40 and 50% of cement content was replaced with FA. Production of Sandcrete hollow blocks Continues Mixing was done mechanically, with cement and FA being mixed first, the fine aggregate was then added while mixing continued, followed by the addition of the required quantity of water until a uniform colour and consistency was achieved. Production of Sandcrete hollow blocks Continues Casting was done manually. The process adopted represent the true situation of hollow Sandcrete block production in most part of Nigeria. Curing was done by sprinkling the blocks with water every morning and evening, until the blocks were saturated. Production of Sandcrete hollow blocks Continues The blocks were assessed at 1, 3, 7, 14, 28, and 56 days curing periods. For each test, three specimen were assessed, and the average value of the three was reported. A total of 288 hollow sandcrete blocks were produced. Production of Sandcrete hollow blocks Continues 3.9 Test on Sandcrete Hollow Blocks 3.9.1 Compressive Strength The compressive strength is a measure of the maturity of blocks. The test was performed in accordance with NIS (1974) specification. ) () (2mm specimen of Area GrossN load failurestrength e compressiv -------- (2) 3.9.2 Density Test This test is aimed at determining the unit weight of the blocks. The test were conducted in accordance to Appendix B.1, BS 2028 (1968) specification. ) () (3m block of Volumekg block of weightDensity - - -(3)

The drying shrinkage of the blocks was determined in accordance with Appendix B.2, BS 2028 (1968) specification. 3.9.3 Shrinkage Test 100 xblock of length Originalblock dried of length block of length OriginalShrinkage - - -(4) The water absorption test are good indicators of the apparent porosity of the blocks.It was performed in accordance with Appendix B.1 NIS (1974) specification. 3.9.4 Water Absorption Test 100 xblock dry of weightabsorped water of Weightabsorption Water - - -(5) 4.0 RESULTS S/N PropertyValue 1 2 3 4 Specific gravity Loose bulk density (kg/m3) Loss on ignition (%) Specific surface (m2/g) 3.15 1350 1.00 2.30 Table 1: Test results for the physical properties of Ashaka Brand of Portland cement Table 2: Test result for the chemical analysis of Ashaka Brand of Portland Cement S/N Oxide compositionPercentage of oxide composition 1. 2. 3. 4. 5. 6. 7. 8. CaO SiO2 Al2O3 Fe2O3 SO3 MgO Na2O K2O 63.7 19.90 5.6 2.90 2.30 1.50 0.20 0.71 Table 3: Particle size distribution results for fine aggregate Total weight of sample = 300g BS Sieve sizeAverage weight retained (g) Average cum retained (g) Average cum wt passing (g) Average % passing Cum. 2.36mm45.3045.30254.7084.9 2.00mm17.9063.20236.878.93 1.18mm106.5169.7130.343.4 600m75.2244.955.118.4 300m31.91276.8123.197.73 150 m11.33288.1411.863.95 63 m7.93296.073.931.31 Receiver3.9330000.00 Specific gravity2.60 Table 4: Silt content test result for fine aggregate Test NoAverage value Average volume of sample (ml) Average volume of silt (ml) Silt content =22.33 1.2 5.37 Silt content= 5 Table 5: Particle size distribution for fly ash (FA) Total weight of sample = 100g BS Sieve size Weight retained (g) Cum Wt retained (g) wt passing (g) % passing 300m00100100.0 212 m3.23.296.896.8 150 m14.818.08282.0 63 m13.0316969.0 Receiver 69.0100-- Table 6: Test results for the Physical properties of fly ash (FA)S/NPropertyValue 1 2 3 4 5 Specific gravity Bulk density (kg/m3) Loss on ignition (%) Moisture content (%) pH 2.25 850 9.4 1.3 9.2 6ColourDark grey Table 7: Test result for the Chemical Analysis of Fly Ash (FA) S/NOxide compositionPercentage of oxide composition 1. 2. 3. 4. 5. 6. 7. 8. SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O SO3 48.0 22.0 7.8 7.0 1.23 0.80 2.23 1.0 Table 8: Pozzolanic activity index for FA/OPC S/N Test specimen (% replacements) 28 days compressive strength (N/mm2) Average compressive strength (N/mm2) 1. 2. 3. 0% ash 0% ash 0% ash 3.28 3.15 3.17 3.20 4. 5. 6.` 30% ash30% ash 30% ash 2.26 2.35 2.29 2.30 *PAI = Pozzolanic activitiy index Table 9: Consistency test result for FA/OPCS/N% Cement replaced by FAConsistency (%) 1033 2534 31035 42037 53039 63540 74041 85043 Table 10: Setting times test results for FA/OPC S/N% Cement replaced by FA Initial setting timeFinal setting time 1059mins234mins 2590mins248mins 310105mins268mins 420118mins281mins 530137mins295mins 635148mins302mins 740162mins310mins 850174mins328min Table 11: Soundness test results for FA/OPC S/N% Cement replaced by FASoundness (mm) 101.5 251.6 3101.8 4202.0 5302.4 6352.6 7402.8 8503.2 Table 12:Compressive Strength of Sandcrete Hollow Blocks Produced with FA at mix ratio 1:6. S/N % of Cement Replaced byFA compressive Strength (N/mm2) 1day 3days 7days 14 days 28 days 56days 1: 61: 61: 61: 61: 61: 6 100.440.851.602.563.603.93 250.400.741.422.343.453.32 3100.370.631.302.213.293.06 4200.250.501.121.962.882.91 5300.150.360.841.462.302.23 6350.080.200.721.331.722.02 7400.000.120.430.981.051.78 8500.000.080.330.650.901.22 Table 13:Compressive Strength of Sandcrete Hollow Blocks Produced with FA at mix ratio 1:8. S/N % of Cement Replaced byFA compressive Strength (N/mm2) 1day 3 days 7 days 14 days 28 days 56 days 1: 81: 81: 81: 81: 81: 8 100.400.791.482.282.903.25 250.360.621.262.092.713.04 3100.300.511.111.982.582.93 4200.200.401.011.732.252.50 5300.100.250.701.301.701.94 6350.000.140.531.181.451.78 7400.000.070.320.750.931.31 8500.000.040.250.400.680.98 Table 14: Density of Sandcrete Hollow Blocks Produced with FA at mix ratio 1:6. S/N % of Cement Replaced by RHA Density (kg/m3) 1day 3 days 7 days 14 days 28days 56 days 1: 61: 61: 61: 61: 61: 6 10 201620021995200619851976 25198619781949198019401941 310194219341928195219041910 420189819011886191218831888 530184018811836188318201840 635181618451800185417921802 740179218151782180817721784 8 50177017931760178217491768 Table 15: Density of Sandcrete Hollow Blocks Produced with FA at mix ratio 1:8 S/N % of Cement Replaced by RHA Density (kg/m3) 1day 3 days 7days 14days 28days 56days 1: 81: 81: 81: 81: 81: 8 10 197619681957197919701958 25195919431922193619221908 310190519021902190618701884 420187818711848188218321838 530182118391802184217941804 635178418221770182317611778 740176917921745178517481756 8 50174817681732175817361739 Table 16:Shrinkage of Sandcrete Hollow Blocks Produced With FA at mix ratio 1:6.

S/N % of Cement Replaced by RHA Shrinkage (%) 1day 3 days 7 days 14 days 28 days 56days 1: 61: 61: 61: 61: 61: 6 10NV0.010.0150.0200.0250.038 25NV0.0110.0180.0200.0300.040 310NV0.0160.0200.0210.0410.042 420NV0.0200.0250.0230.0410.048 5300.0080.0200.0280.0300.0420.051 6350.0080.0220.0300.0350.0420.052 7400.0090.0240.0340.0380.0430.053 8500.0090.0250.0350.0400.0450.053 * NV No Value. Table 17:Shrinkage of Sandcrete Hollow Blocks Produced with FA at mix ratio 1:8 * NV No Value. S/N % of Cement Replaced by RHA Shrinkage (%) 1day 3 days 7days 14 days 28 days 56 days 1: 81: 81: 81: 81: 81: 8 10NV0.0140.0200.0240.0300.039 25NV0.0140.0250.0250.0380.041 310NV0.0190.0290.0250.0450.043 420NV0.0240.0310.0300.0460.049 5300.0080.0250.0340.0320.0470.052 6350.0080.0250.0380.0400.0480.053 7400.0090.0300.0390.0420.0490.054 8500.0090.0300.0410.0450.0500.054 Table 18:Water Absorption of Sandcrete Hollow Blocks Produced With FA at mix ratio 1:6 S/N % of Cement Replaced by FA Water Absorption (%) 1day 3 days 7 days 14 days 28days 56days 1: 61: 61: 61: 61: 61: 6 108.207.606.205.705.104.70 258.257.806.305.805.304.90 3108.307.826.285.985.625.15 4208.407.826.606.185.745.27 5308.427.957.106.405.965.48 6358.428.107.406.405.825.68 7408.448.157.586.396.015.91 8508.468.207.806.486.105.92 Table 19:Water Absorption of Sandcrete Hollow Blocks Produced With FA at mix ratio 1:8. S/N % of Cement Replaced by FA Water Absorption (%) 1day 3days 7days 14days 28 days 56days 1: 81: 81: 81: 81: 81: 8 108.407.907.056.506.025.60 258.508.107.356.856.105.74 3108.518.147.407.026.405.63 4208.508.207.807.286.605.74 5308.548.188.157.506.855.86 6358.568.258.267.476.906.12 7408.588.358.387.516.806.28 8508.588.408.427.706.856.34 5.0 DISCUSSION OF RESULTS 5.1 Materials 5.1.1 Cement The values obtained were all within the range specified by Neville (1982) and BS 12 (1978) Specification S/N Oxide Composition Test results obtained Range specified by BS 12 (1978) Range specified by A.M Neville (1982) 1.CaO63.760 6760 67 2.SiO219.9017 2517 25 3.Al2O35.63 82 8 4.Fe2O32.900.5 6.00 6 5.SO32.301 31 3 6.MgO1.50.1 4.00.1 4.0 7.Na2O0.200.2 1.30.2 1.5 8.K2O0.710.2 1.30.2 1.5 Table 20: Comparison of test results of AshakaBrand of Portland Cement 0.010.020.030.040.050.060.070.080.090.0100.00.01 0.1 1 10 100Percent Passing (%) Figure 1. Particle size Distribution for fine aggregate silt sandGravelMedCoarseCoarse CoarseFine FineMedium Medium5.1.2 FINE AGGREGATE Fine Aggregate (Sand) continues The materials falls within zone 2 Neville (1982) Implying that it is good for concrete works It has a silt content of 5.37% which is less than 6%, it implies that it has a good bond between cement and the fine aggregate Table 21. Comparison of FA and OPC1: Size Distribution Sieve size% Passing(FA) % Passing (OPC) 212m 150m 63m 100 82 69 100 78 65 Table 22. Comparison of FA and OPC 2: Specific Gravity and Bulk density S/NParameterFAOPC 1. 2. S.G Bulk Density 2.25 850Kg/m3 3.15 1350Kg/m3 Comparison Cont. The specific gravity of FA was 29% lower than OPC. The bulk density of FA was 37% lower than OPC. Table 23. FA as Pozzolana S/NParameterFA(%)ASTM C618 (1978) 1. 2. 3. MgO M.C Carbon Content 1.23 1.30 9.4 Max. 4% Max. 1.5% Max. 12% 4. 5. 6. SiO2 Al2O3 Fe2O3 48 22 7.8 The sum of SiO2, Al2O3 and Fe2O3 > 70% TOTAL77.8%> 70% 5.2 Pozzolanic Activity Index PAI for FA blocks = 72% ASTM C 618 (1978) recommends a Minimum PAI value of 70% FA confirmed to be Pozzolanic and can be used as a pozzolanicmaterials 5.3 Effect of Ashes on Cement paste5.3.1 Effect of fly Ash on cement paste 303540450 5 10 20 30 35 40 50Consistency (%) % of fly ash Fig 2. Consistency of OPC/FA paste 0501001502002503003500 5 10 20 30 35 40 50Setting time (mins) % of Fly ash Fig 3 Setting Time of OPC/FA paste Initial setting timeFinal Setting time11.522.533.50 5 10 20 30 35 40 50Soundness (mm) % of fly ash Fig 4. Soundness of OPC/FA paste 00.511.522.51 3 7 14 28 56 (days)Dry Development strength (N/mm2) Curing Period (Days) Fig 5. Compressive strength of Blocks at 20% cement replacement with Fly ash 20% FA for mix 1:620% FA for mix 1:8FA 5.5 Compressive Strength 00.511.522.533.544.50 5 10 20 30 35 40 50Dry development strength (N/mm2) % Replacement of cement with Fly ash Fig 6. Compressive strength of Blocks at 56 days curing period 20% of replace 1:620% of replace 1:8FA The blocks containing 20% FA recorded a maximum compressive strength values of 2.91N/mm2 and 2.50N/mm2 at 56 days curing periods BS 2028 (1968) Recommended a minimum strength of 3.5N/mm2. While FMW (1985) Recommended a minimum strength of 2.1N/mm2. Compressive Strength Continues Based on FMW(1985) recommendation, Sandcrete blocks containing, Blocks containing fly ash of 1:6 sand cement ratio from 0 up to 30% replacement have strength greater than 2.1 N/mm2, when cured at 28, and 56days, while for mix ratio 1:8 from 0 up to 20% replacements have strength greater than 2.1 N/mm2when cured at 28 and 56ays.Compressive Strength Continues Studies conducted by Oyetola andAbdullahi (2003), Rasheed (1992), Adeshola (1993) and Duna et al (2003) assessed the compressive strength of hollow sandcrete blocks produced by reputable manufacturers in Minna, Kaduna, Ilorin, Bauchi and Gombe States.Compressive Strength Continues They obtained maximum compressive strength values of 0.79, 1.06, 0.68, 0.64 and 0.78 N/mm2 respectively. When compared with the compressive strength results obtained from this study i.e. (blocks containing FA), the strengths recorded were higher than those obtained from the states mentioned. Compressive Strength Continues 1800181018201830184018501860187018801890190019101 3 7 14 28 56 (days)Density (Kg/m3) Curing Period (Days) Fig 9. Density of Blocks at 20% cement replacement with FA 20% of replace 1:620% of replace 1:8FA 5.7 Density FA 15501600165017001750180018501900195020000 5 10 20 30 35 40 50Density (Kg/m3) % Replacement with FA Fig 10. Density of Blocks at 56 days curing period 20% of replace 1:620% of replace 1:8BS 2028 (1968) specifies that the density for type A and B blocks should be within the range of (625-2100 kg/m3). Therefore the values obtained for the densities were all within the range specified for sandcrete blocks. Density Continues FA 00.010.020.030.040.050.061 3 7 14 28 56 (days)Shrinkage (%) Curing Period (Days) Fig 11. Shrinkage of Blocks at 20% cement replacement with FA 20% of replace 1:620% of replace 1:85.8 Shrinkage FA 00.010.020.030.040.050.060 5 10 20 30 35 40 50Shrinkage (%) % Replacement with FA Fig 12. Shrinkage of Blocks at 56 days curing period 20% of replace 1:620% of replace 1:8The shrinkage is one of themeasures of assessing the quality of blocks;The test results reveal that at the first day curing, there were no noticeable shrinkages Shrinkage Cont. Higher shrinkage values were obtained on blocks made with 1:8 mix ratios than that of mix ratio 1:6. This is also in agreement with Owolabi (1992) which confirms that shrinkages are well pronounced in leaner mix than in rich mixes. Shrinkage Continues The magnitude of the shrinkage is small and does not adversely affect the volume of the sandcrete blocks. Shrinkage Continues The shrinkage values obtained were also in conformity with the values obtained by Rasheed (1992), Adeshola (1993) and Matawal et al (2006), which gives their shrinkage values as 0.03, 0.02 and 0.05% respectively. Shrinkage Continues BS 2028 (1968) specifies that the shrinkage should not be more than 0.07%. Shrinkage Continues FA 0123456789101 3 7 14 28 56(days)Water absorption % Curing Period (Days) Fig 13. Water absorption of Blocks at 20% cement replacement with FA 20% of replace 1:620% of replace 1:85.9 Water Absorption FA 012345670 5 10 20 30 35 40 50Water absorption % % Replacement with FA Fig 14. Water absorptionof Blocks at 56 days curing period 20% of replace 1:620% of replace 1:8The test results reveal that blocks made with 1: 8 mix ratio recorded higher water absorption than those made with 1:6 mix ratio for all the replacement levels and curing periods.Water Absorption Continues NIS (1974) recommends maximum water absorption of up to 25% by weight. Therefore the values obtained for the water absorption are all within the specified values. Water Absorption Continues 6.0 CONCLUSION AND RECOMMENDATION 6.1 CONCLUSION This work is aimed at assessing the possibility of using FA as pozzolana in the production of sandcrete blocks.A series of tests on the engineering properties of the hollow sandcrete blocks containing FA were conducted. Test results on the blocks were compared with that of the control, international and local standards and test results from blocks produced from reputable commercial manufacturers CONCLUSION Continues Based on the results and discussion made, the following conclusions can be drawn. CONCLUSION Continues 1. The sum of pozzolanic oxides of the FA used for the study was obtained as 77.8%. 2. The specific gravity of FA was 2.25. The obtained value was 29%lower than that of ordinary Portland cement, OPC. CONCLUSION Continues 3. The bulk density of FA obtained was 850kg/m3. The value obtained was 37%lower than that of ordinary Portland cement, OPC. 4. The pozzolanic activity index PAI, determined at 30% ash to cement replacement was 72% for FA. CONCLUSION Continues 5. The normal consistency of the paste increases as the proportion of the ash increases. The average consistency of FA cement paste was 38%. CONCLUSION Continues 6. The initial and final setting times increase as the percentages of the ashes increased. All the values obtained fall within the values recommended by BS 12 (1978). CONCLUSION Continues 7. The soundness increases slightly with increase in percentage of ash. The maximum soundness values of 2.8mm was obtained for FA cement paste. All the values obtained were within the values recommended by BS 12 (1978). CONCLUSION Continues 8. The quality of the raw materials used for the sandcrete blocks (cement and sand) were assessed; the test results show that the materials meet the requirements specified by the standards, BS 12 (1978), BS 882 part 1 and 2 (1973). CONCLUSION Continues 9. There were similarities in the particle size distribution of FA and OPC used in the hollow sandcrete blocks production, making the materials to blend properly. CONCLUSION Continues 10. The compressive strength increases with increase in curing periods. 11. The compressive strength decreased with increase in FA content.CONCLUSION Continues 12. Based on FMW(1985) recommendation, Sandcrete blocks containing, Blocks containing fly ash of 1:6 sand cement ratio from 0 up to 30% replacement have strength greater than 2.1 N/mm2, when cured at 28, and 56days, while for mix ratio 1:8 from 0 up to 20% replacements have strength greater than 2.1 N/mm2

when cured at 28 and 56days.CONCLUSION Continues 13. The sandcrete blocks made with 1:6 (cement: sand) ratio had higher densities than those made with 1:8 mixes.14. The densities of the blocks obtained were all within the values specified by BS 2028 (1968).CONCLUSION Continues 15. The shrinkage of the sandcrete blocks increased slightly as the percentages of FA increases; and also increased with increase in curing period.16. The higher shrinkage values were obtained on blocks made with 1:8 (cement: sand) mix ratio as compared with those made with 1:6 mixes. CONCLUSION Continues 17. The shrinkage values obtained were all within the values specified by the standards.18. The water absorption increased with increase in percentage of FA content and decreases as the curing period increases. CONCLUSION Continues 19. Higher water absorption values were obtained for blocksmade with 1:8 (cement: sand) mix ratio as compared with those made with 1:6 mixes.20. The water absorption values obtained were all within the values specified by British and Nigerian standards. CONCLUSION Continues 6.2 Recommendation Based on the results obtained from this study, the following recommendations can be made: There is the need to study the noise, heat absorption (acoustic and thermal) including the electrical resistivityof the pozzolanic blocks. There is the need to construct a house using the blocks containing FA, so as to reflect the real situation. The constructed house will help in assessing the strength of the wall on dry and wet situations as well as to evaluate the actual cost of construction and compared with that of blocks with no ash. Recommendation Continues Thank You