Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 95 EFFECT OF MAGNETIZED WATER ON THE PROPERTIES OF CEMENT MORTARS AT THE EARLIER AGES Adnan Flayih Hassan Qadisiya University / College of Engineering Civil Engineering Department Abstract This study had been conducted to investigate the influence of magnetized water on the properties of cement mortars such as initial and final setting time, consistency and compressive strength with various water/cement ratios at the ages of 1 and 7 day. Results of (50) specimens with different shapes had been adopted, which represented mortars specimens having compressive strength ranging from (5.5) to (32.5) MPa, initial setting time ranging from (4) to ( 32) minutes and final setting time ranging from (303) to (546) minutes, by using two types of mixing water , first one is tap water , and the other is magnetized water.The results showed that the use of magnetized water in producing cement mortars lead to increase in the compressive strength and decreasing in the initial and final setting time with compare to use of tap water. Results also showed that the optimum water/cement ratio give best compressive strength under the conditions of this study was (0.45). Key words: Initial setting time, final setting time, consistency, compressive strength, tap water, magnetized water. منتية في األعمار المبكرةستأثير الماء الممغنط على خواص المونة ال دنان فليح حسنـــــع آلية الهندسة/ جامعة القادسية قسم الهندسة المدنية :الخالصة آزمن التجمد االبتدائي و , ةتيسمنلامونة ال عن تأثير استخدام الماء الممغنط على خواص أجريت هذه الدراسة للتحري . يوم7 و 1مقاومة االنضغاط تم فحصها بعمر , مختلفة ) سمنت / ماء( ائي و القوام و مقاومة االنضغاط باستخدام نسب النه ) 4 (بينزمن تجمد ابتدائي تراوح , MPa) 32.5 ( و) 5.5 ( بين ت نموذج ذات مقاومة انضغاط تـــــراوح50تم اعتماد نتائج األول هو ماء الحنفية و , دقيقة وباستخدام نوعين من ماء الخلط ) 546 (و) 303 ( اوح بينهائي تـردقيقة و زمن تجمد ن) 32 ( و يؤدي إلى زيادة مقاومة االنضغاط و يةمونة السمنتالالنتائج بينت إن استخدام الماء الممغنط في إنتاج . الثاني هو الماء الممغنط أعطت أعلى ) سمنت/ ماء( أما أفضل نسبة . قارنة مع استخدام ماء الحنفية نقصان في زمن التجمد االبتدائي و النهائي بالم ).0.45( ظروف هذه الدراسة آانت مقاومة انضغاط في ظل Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 96 Introduction The water in the cement paste found in three types: free water which found in capillary pores, combined and adsorbed water, where the later types un-evaporation water and contribution in cement hydration. On the other hand the quality of used water plays a significant role: impurities in water may interfere with the setting of the cement, and adversely affect the strength of cement mortar or cause staining of its surface. For these reasons, the suitability of water for mixing should be considered. In many projects specification, the quality of water is covered by a clause saying that water should be fit for drinking. Such water very rarely contains dissolved inorganic solid in excess of 2000 parts per million (ppm), and as a rule less than 1000 (ppm). The use of potable water as mixing water is generally satisfactory, there are some exceptions, for instance, in same arid areas, local drinking water is saline and may contain undesirable amounts of alkali carbonates and bicarbonates which could contribute to the alkali-silicate reaction(1). Over the past years, research has been shown that magnetic treatment of water may reduce “hardness” caused primarily by calcium and magnesium. Water treatment magnets can prevent deposits of these minerals on the inside of the pipe walls, and descale the existing buildup of solids(2). However, still limited amount of published literature is available about the effect of magnetized water on the properties of Portland cement mortar or concrete. Significant of research The main aim of this study is to remarking experimentally the behavior of cement mortars at earlier ages by using mechanism of water magnetizer depending upon bipolar system with different proportions of water/cement ratio ; therefore provide information on compressive, initial and final setting time of this type of cement mortars. Also, to compare with the results of tap water. Experimental Program Available materials in Iraq were used in this research to produce cement mortars with mix proportions 1 (cement) : 3 (sand ) and by using two types of mixed water , the first one is tap water , and the other is magnetized water with discharge of (0.015 liter/second) . For the two types of water the (W/C) ratios used were 0.4, 0.45, 0.5, 0.55 and 0.6. The specimens tested for consistency, initial and final setting time. On the other hand, the compressive strength was measured for the cement mortar in 1 and 7 days. The specimens at age of (7) days cured in water then tested for compressive strength. Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 97 Materials Used in This Research 1.Cement Sulphate resistance Portland cement type (V) manufactured by Yamama cement factory was used in this study. The essential physical properties of this type of cement were tested in this study , as results of this research refer to that , while the chemical properties of this cement were conformed to standard specifications. 2. Fine Aggregate Normal natural weight sand from the Wilayt Ali source was used as a fine aggregate, before its incorporation into cement mortar mix, the sand was sieved, and used with a saturated surface dry condition. The properties of the used sand in this study were conformed to the requirement of Iraqi standard specification No.45-1984(3) zone (2) as shown in Table (1). 3. Mix Water Two types of water were used in this study, the first one is tap water and the second one is magnetized water .The magnetized water was produce by passing of tap water in the bipolar system from the positive north to the negative south perpendicular intersection the lines of magnetize, this mechanism obtained from the use of the magnetizer apparatus locally manufacture by Al-Juthari(4) as shown in the Fig. (1). This apparatus have four circles, each circle contains two magnates with strength 500 Gauss and discharge 2000 liter / hour. Test Procedures 1.Consistency , Initial and Final Setting Time The initial and final setting time test were carried out according to ASTM Designation: C 191(5) by using Vicat needle apparatus, Figs. (2) and (3), which consists of a movable rod weighing 500 grams; one end, the plunger end, being 10 mm in diameter for a distance of at least 5 cm and the other end having a movable steel needle, 1 mm in diameter and 5 cm in length. The rod is reversible and can be raised or lowered by the set screw, which has an adjustable indicator. The latter moves over a graduated scale attached to the frame. The cement paste is held in a circular mould, which has an inside diameter of 5 cm and has a height of 5 cm. The average results of three specimens were adopted at each test. 2. Compressive Strength The compressive Strength test was determined according to BS.1881-part 116 -1989(6). A cube specimens with dimensions 100 mm were tested by using standard testing machine with a capacity of 2000 KN, Fig.(4).The test was conducted at ages of (1) and (7) day and the average results of three specimens were adopted at each test. Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 98 Results and Discussion The results of the experimental work for this research are listed in Table (2), and then represented in Figures (5) to (16). Figures (5) and (6) represent the effect of magnetized water on the initial and final setting time respectively. From these figures with addition to Figures (13) and (14) can be seen that the increasing of initial and final setting time for both types of mix water with the increasing of water/cement ratio. The percentages of increasing in the initial setting time at W/C = 0.6 with respect to W/C = 0.4 were 220% and 525% for tap and magnetized water respectively, while the corresponding percentages of increasing in finial setting time at W/C = 0.6 with respect to W/C = 0.4 were 45.6 % and 44.8 % for tap and magnetized water respectively. This may be attributed to excessive water quantity and its inverse effect on the setting, where lead to elongation the setting time of cement paste. Figures (5), (6), (9) and (10) showed that the use of magnetized water lead to reduce the initial setting time with percentage of 60% for W/C = 0.4 and 21.8% for W/C = 0.6 compared with the use of tap water. In the other hand the corresponding percentages of decreasing in finial setting time were 19.2% for W/C = 0.4 and 19.6 % for W/C = 0.6 compared with the use of tap water. This may be attributed to the use of magnet mechanism, which lead to redistribution of the water molecules and change interior angle between them, finally decreasing the surface tension(7), increasing the solubility of water and cause the setting in short time. Figures (7) and (8) represent the effect of magnetized water on the compressive strength of cement mortar at ages of (1) and (7) day respectively. From these figures can be seen that the use of W/C = 0.45 give higher value of compressive strength in both ages. This is related to the volume of hydration products and the magnitude of calcium silicate hydrate (C-S-H) gel in the total hydration volume; where the C-S-H gel play essential role in the progressive of strength for the cement paste, where the ( W/C = 0.4 ) having lower C-S-H gel due to finding unhydration cement particles in the volume of hydration products, also (W/C > 0.45) give lower C-S-H gel due to finding percent of capillary pores filling with water. Figures (7), (8), (11) and (12) demonstrated that the use of magnetized water lead to increase the compressive strength at the earlier ages. The percentages of increasing in the compressive strength at age of (1) day due to use magnetized water compared with the specimens made with tap water with W/C = 0.4 and 0.6 were 9 % and 8.3% respectively, while the corresponding percentages values for the compressive strength at age of (7) day were 22.7% and 20%. This performance may be due to shortly setting time of cement paste, increasing its solubility and ability to form gel of calcium silicate hydrate, (i.e. increasing the speed of hydration to form C- S-H gel). Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 99 Figures (15) and (16) represented percentage of increasing in compressive strength at ages of (1) and (7) days for two type of mixed water compared with W/C = 0.4. These Figures showed that the percentage of increasing in compressive strength decreased with the increasing of W/C ratio. This behavior may be due to inverse effect of excessive water quantity on the strength, where lead to produce more porosity cement paste and increase the capillary pores filling with water The consistency test results didn't give apparent performance, where all experimental results (unless cement mortar made by magnetized water with W/C = 0.4) have full penetration of steel needle to the surface of cement mortar, however can be conclude that the magnetized water lead to decrease the consistency, where the result of steel needle penetration at (W/C = 0.4) was equal to zero. This behavior may be related to the decreasing the setting time by using magnetized water. The best fits lines and curves for the results of this study were draw with Figures (5) to (8), and can be express by the following equations according to the Graphed program: 1. Initial setting time A. The equation of best fit line for cement mortar made with tap water: Y= 114 X – 36.8 (1) With Coefficient of determination (R-Squared) = 0.976 B. The equation of best fit line for cement mortar made with magnetized water: Y=102 X – 38 (2) With Coefficient of determination (R-Squared) = 0.9633 2. Final setting time A. The equation of best fit line for cement mortar made with tap water: Y= 882 X – 6.8 (3) With Coefficient of determination (R-Squared) = 0.969 B. The equation of best fit line for cement mortar made with magnetized water: Y= 676 X – 27.6 (4) With Coefficient of determination (R-Squared) = 0.989 3. Compressive strength at age of (1) day A. The equation of best fit curve from 4th degree for cement mortar made with tap water: Y= -23333 X4+ 47666 X3 – 36341 X2 + 12250 X – 1533 (5) With Coefficient of determination (R-Squared) for 4th degree = 1 B. The equation of best fit curve from 4th degree for cement mortar made with magnetized water: Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 100 Y= -16666 X4+ 35000 X3 – 27458 X2 + 9527 X – 1225 (6) With Coefficient of determination (R-Squared) for 4th degree = 1 4. Compressive strength at age of (7) days A. The equation of best fit curve from 4th degree for cement mortar made with tap water: Y = -76666 X4+ 157000 X3 – 120008 X2 + 40557 X – 5085 (7) With Coefficient of determination (R-Squared) for 4th degree = 1 B. The equation of best fit curve from 4th degree for cement mortar made with magnetized water: Y = -66666 X4+ 137333 X3 – 105633 X2 + 35926 X – 4525 (8) With Coefficient of determination (R-Squared) for 4th degree = 1 Conclusions The following points are fixed depending on the analysis of the results obtained from this study. 1. There is apparently different between the results adopted from used of magnetized water and tap water in producing cement mortar. 2. The initial and final setting times decreasing by using magnetized water. 3. The compressive strength of cement mortars at earlier ages significantly increase by using magnetized water. 4. The optimum water /cement ratio gave best compressive strength under the conditions of this study was 0.45. 5. The consistency of cement mortar decreasing by using magnetized water as a mixed water. References 1. A.M.Neville ,"Properties of concrete",3rd edition, 183 p,. 2. Master Magnetics Inc., "Water treatment magnets ",Watermags. Pdf, Internet file, pp1-4. . بالسمنت البورتالنديةالخاص, 1984 -5المواصفة القياسية العراقية رقم .3 4. Al-Juthari , Hiawe Wawa "Technical paper " , Qadissiya University, pp 1-3, 2006. 5. ASTM Designation: C 191 "Standard Test Method for setting Time of Hydraulic Portland Cement by Using Vicat Needle ", Pdf, Internet file, 50 p. 6. BS.1881. Part 116" Method for Determination of Compressive Strength of Concrete Cubes ", British Stander Institution, 1992, 3 p. 7. Al-Juthari, Hiawe Wawa "Effect of Irrigation Water Quality, Magnetic Water and Potassium Fertilizer Levels on Some Chemical Properties of Soil, Growth and Yield of Corn", M.Sc. Thesis, University of Baghdad – College of Agriculture2006, 19 p. Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 101 Table (1): Properties of sand used throughout this study Table (2): The results of experimental work 1.Grading Test result Iraqi standard specification No.45-1984 Size of sieve % passing Zone 1 Zone 2 Zone 3 Zone 4 10 mm 100 100 100 100 100 4.75 mm 98.6 90-100 90-100 90-100 95-100 2.36 mm 92.0 60-95 75-100 85-100 95-100 1.18 mm 89.0 30-70 55-90 75-100 90-100 600 µ m 51.1 15-34 35-59 60-79 80-100 300 µ m 25.0 5-20 8-30 12-40 15-50 150 µ m 8.80 0-10 0-10 0-10 0-15 2.Deleterious Substations Test result Iraqi standard specification No.45-1984 ( Allowable limit)% Material % Deleterious Substations Natural sand Sand of crushed gravel Lightness materials 0.07 1 1 Percentage of clay 0.00 1 1 Materials passing from size 75µ m 2.40 5 15 Salts as SO3 0.41 0.5 for the foundation concrete and the parts exposed for water and 0.75 for other 0.5 for the foundation concrete and the parts exposed for water and 0.75 for other Consistency Initial setting time Final setting time Compressive strength Tap water (MPa) Magnetizer water (MPa) W/C Tap water (mm) Magnetizer water (mm) Tap water (min.) Magnetizer water (min.) Tap water (min.) Magnetizer water (min.) 1 day 7 days 1 day 7 days 0.40 50 0 10 4 375 303 5.5 22 6 27 0.45 50 50 14 7 390 327 7 27 8 32 0.50 50 50 18 13 439 366 6.5 25 7.5 30 0.55 50 50 27 16 489 393 6.5 24.5 7 29 0.60 50 50 32 25 546 439 6 22.5 6.5 27 Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 102 Figure (1): Magnetizer Apparatus Figure (2): Vicat Needle Apparatus Figure (3): Vicat Needle Apparatus with Specimen Figure (4): Compression Machine Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 103 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 5 10 15 20 25 30 35 In iti al S et tin g T im e (m in ut es ) Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (5): Effect of Magnetized Water on the Initial Setting Time of Cement Mortar. 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 275 325 375 425 475 525 575 F in al S et ti ng T im e (m in ut es ) Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (6): Effect of Magnetized Water on the Final Setting Time of Cement Mortar. Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 104 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 F in al S et tin g T im e (m in ut es ) Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (7): Effect of Magnetized Water on the Compressive Strength of Cement Mortar at Age of (1) Day. 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 20 22 24 26 28 30 32 34 36 F in al S et ti ng T im e (m in ut es ) Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (8): Effect of Magnetizer Water on the Compressive Strength of Cement Mortar at Age of (7) Days. Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 105 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 10 20 30 40 50 60 70 P er ce nt ag e of d ec re as in g in in iti al s et tin g ti m e % Figure (9):Percentage of Decreasing in Initial Setting Time Due to Use Magnetized Water Compared with Cement Mortar Made by Tap Water 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 2 4 6 8 10 12 14 16 18 20 22 24 P er ce nt ag e of d ec re as in g in fi na l s et tin g ti m e % Figure (10): Percentage of Decreasing in Final Setting Time Due to Use Magnetized Water Compared with Cement Mortar Made by Tap Water Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 106 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 2 4 6 8 10 12 14 16 18 P er ce nt ag e of in cr ea si ng in c om pr es si ve s tr en gt h % Figure (11): Percentage of Increasing in Compressive Strength at (1) Day Due to Use Magnetized Water Compared with Cement Mortar Made by Tap Water 0.35 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 2 4 6 8 10 12 14 16 18 20 22 24 26 P er ce nt ag e of in cr ea si ng in c om pr es si ve s tr en gt h % Figure (12): Percentage of Increasing in Compressive Strength at (7) Days Due to Use Magnetized Water Compared with Cement Mortar Made by Tap Water Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 107 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 100 200 300 400 500 600 Pe rc en ta ge o f i nc re as in g in in iti al s et tin g tim e co m pa re d w ith W /C =0 .4 Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (13): Percentage of Increasing in Initial Setting Time For Two Type of Mixed Water Compared With W/C = 0.4 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 10 20 30 40 50 P er ce nt ag e of in cr ea si ng in fi na l s et tin g tim e co m pa re d w ith W /C =0 .4 Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (14): Percentage of Increasing in Final Setting Time For Two Type of Mixed Water Compared With W/C = 0.4 Al-Qadisiya Journal For Engineering Sciences Vol. 1 No. 1 Year 2008 108 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 5 10 15 20 25 30 35 Pe rc en ta ge o f i nc re as in g in c om pr es si ve s tr en gt h co m pa re d w ith W /C =0 .4 Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (15): Percentage of Increasing in Compressive Strength at (1) Day For Two Type of Mixed Water Compared With W/C = 0.4 0.40 0.45 0.50 0.55 0.60 0.65 (W/C) Ratio 0 5 10 15 20 25 30 35 P er ce nt ag e of in cr ea si ng in c om pr es si ve s tr en gt h co m pa re d w it h W /C =0 .4 Cement Mortar With Tap Water Cement Mortar With Magnetized Water Figure (16) Percentage of Increasing in Compressive Strength at (7) Days For Two Type of Mixed Water Compared With W/C = 0.4