The Usage of Polyethylene Terephthalate in Grout. Manoel Ferreira de Abreu Junior

Transcription

1 The Usage of Polyethylene Terephthalate in Grout Manoel Ferreira de Abreu Junior A project submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of Master of Science Fernando Fonseca, Chair Paul Richard Kyle Rollins Department of Civil and Environmental Engineering Brigham Young University April 2014 Copyright 2014 Manoel Ferreira de Abreu Junior All Rights Reserved

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3 ABSTRACT The usage of Polyethylene Terephthalate in Grout Manoel Ferreira de Abreu Junior Department of Civil and Environmental Engineering, BYU Master of Science This research is conducted in order to try to introduce a new material in the grout mix. Recycled Polyethylene Terephthalate (PET) come from water bottles and after recycling are transformed in pellets. The research is changing the coarse aggregate for PET. It was done changing respectively 5%, 10%, 15% and 20%. A control mix was used to compare the modified ones with it. The results were very significant indicating that all cylinders exceeded the 2000 psi (14 MPa) minimum compressive strength that the ASTM requires. The usage of Polyethylene Terephthalate in grout is posssible. The maximum stress found in all groups was above the minimum ASTM specification. Keywords: Grout, PET, Polyethylene Terephthalate, compressive strength.

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5 ACKNOWLEDGEMENTS Much credit is due to Dr. Fonseca for his guidance, patience and assistance helping me with this research and my academic progress. Dr. Richards and Dr. Rollins showed their interest in the success of their students. Marglen Industries on the person of Ben McElrath, for donating the PET pellets used in this research. David Anderson and Rodney Mayo are acknowledging for their assistance in the laboratory helping in each part of the process. Great encouragement and confidence was provided for my father Manoel, mother Macrina, uncle Mario, aunt Unezi, aunt Zelia, my mother-in-law Otacilia. Most importantly, I thank my wife Dalianny for her support and understanding of my educational pursuits and my two sons Thomas and Alex for the smile and hugs that they gave me every day making this time been a lot easier.

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7 TABLE OF CONTENTS LIST OF TABLES... vii LIST OF FIGURES... ix 1 INTRODUCTION Fundamentals Motivation Scope Outline of Report BACKGROUND Literature Review Polyethylene Terephthalate pellets General use of PET Relevant requirements for Grout PROCEDURE Mix Design Specimen Construction Specimen Testing OBSERVATION AND RESULTS Overview Results Data Treatment Statistical Analysis at Day Statistical Analysis for Day CONCLUSION v

8 REFERENCES Appendix A. PICTURES vi

9 LIST OF TABLES Table 1 Mix Design...8 Table 2 Temperature and Slump...10 Table 3 Group 1 and 2 Max. Stress at 7 days...22 Table 4 Group 3, 4 and 5 Max. Stress at 7 days...22 Table 5 Group 1 and 2 Max. Stress at 28 days...23 Table 6 Group 3, 4 and 5 Max. Stress at 28 days...23 Table 7 Analysis of variance table for 7 days...26 Table 8 Difference from the control for 7 days...27 Table 9 Analysis of variance table for 28 days...28 Table 10 Difference from the control for 28 days...28 Table 11 Increase in Compressive Strength...30 vii

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11 LIST OF FIGURES Figure 1 - Pellets of PET...7 Figure 2 - Mechanical Mixer...9 Figure 3 Slump Apparatus...11 Figure 4 - Identifying Specimens...11 Figure 5 Group of Specimens...12 Figure 6 - Capping...12 Figure 7 - Sulfur used for capping...13 Figure 8 - Leaking on the top...15 Figure 9 - Leaking on the floor...16 Figure 10 - Stress versus Deformation for 7 Days for Group Figure 11 - Stress versus Deformation for 7 Days for Group Figure 12 - Stress versus Deformation for 7 Days for Group Figure 13 - Stress versus Deformation for 7 Days for Group Figure 14 - Stress versus Deformation for 7 Days for Group Figure 15 - Stress versus Deformation for 28 Days for Group Figure 16 - Stress versus Deformation for 28 Days for Group Figure 17 - Stress versus Deformation for 28 Days for Group Figure 18 - Stress versus Deformation for 28 Days for Group Figure 19- Stress versus Deformation for 28 Days for Group Figure 20 - Box plot from 7 days with outlier...24 Figure 21 - Box plot from 7 days without outlier...24 Figure 22 - Box plot from 28 days with outlier...25 Figure 23 - Box plot from 28 days without outlier...25 ix

12 Figure 24 - Difference from the control for 7 days...27 Figure 25 - Difference from the control for 28 days...29 Figure 26 Spec. 7,1, Figure 27 Spec. 7,1, Figure 28 Spec. 7,1, Figure 29 Spec. 7,1, Figure 30 Spec. 7,1, Figure 31 Spec. 7,1, Figure 32 Spec. 7,1, Figure 33 Spec. 7,1, Figure 34 Spec. 7,1, Figure 35 Spec. 7,1, Figure 36 Spec. 7,1, Figure 37 Spec. 7,2, Figure 38 Spec. 7,2, Figure 39 Spec. 7,2, Figure 40 Spec. 7,2, Figure 41 Spec. 7,2, Figure 42 Spec. 7,2, Figure 43 Spec. 7,2, Figure 44 Spec. 7,2, Figure 45 Spec. 7,2, Figure 46 Spec. 7,2, Figure 47 Spec. 7,2, Figure 48 Spec. 7,3, x

13 Figure 49 Spec. 7,3, Figure 50 Spec. 7,3, Figure 51 Spec. 7,3, Figure 52 Spec. 7,3, Figure 53 Spec. 7,3, Figure 54 Spec. 7,3, Figure 55 Spec. 7,3, Figure 56 Spec. 7,3, Figure 57 Spec. 7,3, Figure 58 Spec. 7,3, Figure 59 Spec. 7,4, Figure 60 Spec. 7,4, Figure 61 Spec. 7,4, Figure 62 Spec. 7,4, Figure 63 Spec. 7,4, Figure 64 Spec. 7,4, Figure 65 Spec. 7,4, Figure 66 Spec. 7,4, Figure 67 Spec. 7,4, Figure 68 Spec. 7,4, Figure 69 Spec. 7,4, Figure 70 Spec. 7,5, Figure 71 Spec. 7,5, Figure 72 Spec. 7,5, Figure 73 Spec. 7,5, xi

14 Figure 74 Spec. 7,5, Figure 75 Spec. 7,5, Figure 76 Spec. 7,5, Figure 77 Spec. 7,5, Figure 78 Spec. 7,5, Figure 79 Spec. 7,5, Figure 80 Spec. 28,1, Figure 81 Spec. 28,1, Figure 82 Spec. 28,1, Figure 83 Spec. 28,1, Figure 84 Spec. 28,1, Figure 85 Spec. 28,1, Figure 86 Spec. 28,1, Figure 87 Spec. 28,1, Figure 88 Spec. 28,1, Figure 89 Spec. 28,1, Figure 90 Spec. 28,1, Figure 91 Spec. 28,2, Figure 92 Spec. 28,2, Figure 93 Spec. 28,2, Figure 94 Spec. 28,2, Figure 95 Spec. 28,2, Figure 96 Spec. 28,2, Figure 97 Spec. 28,2, Figure 98 Spec. 28,2, xii

15 Figure 99 Spec. 28,2, Figure 100 Spec. 28,2, Figure 101 Spec. 28,2, Figure 102 Spec. 28,3, Figure 103 Spec. 28,3, Figure 104 Spec. 28,3, Figure 105 Spec. 28,3, Figure 106 Spec. 28,3, Figure 107 Spec. 28,3, Figure 108 Spec. 28,3, Figure 109 Spec. 28,3, Figure 110 Spec. 28,3, Figure 111 Spec. 28,3, Figure 112 Spec. 28,3, Figure 113 Spec. 28,4, Figure 114 Spec. 28,4, Figure 115 Spec. 28,4, Figure 116 Spec. 28,4, Figure 117 Spec. 28,4, Figure 118 Spec. 28,4, Figure 119 Spec. 28,4, Figure 120 Spec. 28,4, Figure 121 Spec. 28,4, Figure 122 Spec. 28,4, Figure 123 Spec. 28,4, xiii

16 Figure 124 Spec. 28,5, Figure 125 Spec. 28,5, Figure 126 Spec. 28,5, Figure 127 Spec. 28,5, Figure 128 Spec. 28,5, Figure 129 Spec. 28,5, Figure 130 Spec. 28,5, Figure 131 Spec. 28,5, Figure 132 Spec. 28,5, Figure 133 Spec. 28,5, Figure 134 Spec. 28,5, xiv

17 1 INTRODUCTION 1.1 Fundamentals This chapter will describe the terms and concepts necessary for understanding this research. This will enable those that are unfamiliar with masonry to understand the terms and subsequently the research. Masonry walls are constructed using masonry units, grout, mortar and reinforced steel. Masonry units, grout and mortar have several fundamental materials in common, such as Portland cement, aggregate (sand and gravel) and water. The difference between the masonry units, grout and mortar is the proportions of cement, aggregate and water in the mix design. Mix design is how much of each material is used to create one of these parts. Grout fills the cells of the masonry units and bonds the reinforcement to the units. Most of the time the calculations are made so that the walls can resist wind and earthquakes loads. A great percentage of buildings built today have at least some part of them that uses masonry walls to help withstand expected wind and earthquake loads. 1.2 Motivation The research was conducted in order to find a way where masonry can be more environmentally friendly. The use of recycled water bottle pellets in grout can show all 1

18 individuals, and especially engineers, the ease and the importance of using recycled materials in construction. The construction industry is one place where many recycled materials can be used to help decrease the amount of waste in landfills. The fabrication process of one pound of pellets uses 18 plastic water bottles (20 oz. size). 1.3 Scope In order to initially evaluate the effect of Polyethylene Terephthalate (PET) on the compressive strength of grout, this research measured the compressive strength of cylindrical specimens. The experiment consisted of five different grout mixes. The first mix was a control group using a 100% coarse aggregate mixture, while the other four mixes substituted PET to the coarse aggregate at rates of 5%, 10%, 15% and 20%, respectively. This replacement was done using a relationship between the weight and volume of the materials. To obtain the results, compressive strength tests were conducted at both 7 and 28 days after casting. A minimum of ten samples were tested for each group on each day. 1.4 Outline of Report This report is divided into five parts: the introduction, the background, the procedures, the results and the conclusion and suggestions. The background, given in chapter 2, will introduce the materials that were used in the reseach as well as discuss the findings of other related studies. The procedures, given in chapter 3,will explain how the research was conducted. It will also provide all of the American Society for Testing Material (ASTM) standards used in each step of the experiment. 2

19 The results are presented in chapter 4 and will show the data that was collected, various charts, how the data was treated before statistical analysis and the statistical analysis itself. The conclusion and suggestions for future research are given in chapter 5. 3

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21 2 BACKGROUND 2.1 Literature Review This chapter shows the literature review for this research Polyethylene Terephthalate pellets Polyethylene Terephthalate (PET) is a very difficult material to decompose and therefore recycled PET has been used in many different industries with the intent of minimizing the amount of it in landfills. In the construction industry to date, there has been some research conducted experimenting with its use in concrete [1] General use of PET The first research found using PET in concrete was in 1993 when Bayasi and Zeng studied the effects of PET on air content, slump and inverted slump. They analyzed the effects and concluded that the slump and air content in the mixture increased with the addition of PET in concrete [12]. Silva in 2005 conducted a research using PET as a fiber for reinforced mortar. He concluded that the amount of PET tested had no effect on the compressive, tensile and flexural strength [13]. Ochi in 2007 conducted additional research using PET as a fiber for reinforced concrete. He concluded that PET is easy to handle [14]. Many other research projects have 5

22 shown the successful substitution of small PET particles in the place of sand in cement mix [2]. An investigation was conducted to use PET in lightweight concrete [2]; the material used in that research was shredded waste of PET Relevant requirements for Grout Grout is a cementitious mixture used in most cases to bond masonry units and steel reinforcement together (11). Grout is typically a mix of aggregate (fine and coarse), water and Portland cement. ASTM C476 Standard Specifications for Grout Masonry give the requirements that need to be followed when grout is designed. For the comprehensive strength test the Standard says in item , The grout should be mixed to a slump of 8 to 11 inches as determined by Test Method C143/C143M and shall have a minimum compressive strength of 2000 psi (14 MPa) at 28 days [5]. The high slump grout is necessary so the grout can properly fill the cavities or cells(11). Although there have been some studies on using PET in concrete, no research specific to PET in grout has been found. Because of this lack of prior work on PET in grout, this research project followed similar methods as those used in the PET/concrete studies. 6

23 3 PROCEDURE 3.1 Mix Design The control mix used in this project was the same mix used in a previous experiment conducted on grout [3]. From the control mix four other mixes were created by adding Polyethylene Terephthalate (PET) pellets made from recycled water bottles. Figure 1 - Pellets of PET Each mix had a different percentage of pellets that was inserted into the mixture, thereby decreasing the amount of gravel in the mixture proportionately. Since PET weighs considerably less than coarse aggregate, an adjustment in the calculations had to be made. First, the volume of the coarse aggregate that would normally be added to the mixture (measured by its weight) was 7

24 calculated. Then this same volume was used to determine the amount of PET pellets to add to the mixture in place of the aggregate, depending on the sample group. There were four sample groups in the experiment, each with a different percentage of aggregate to be replaced by the pellets upon mixture. The amount changed was five percent in the first modified group, ten percent in the second modified group, fifteen percent in the third modified group and twenty percent on the fourth modified group. The table below shows how much of each item was added to each mixture (Table 1). Table 1 Mix Design Material Group 1 Group 2 Group 3 Group 4 Group 5 Kg Lb Kg Lb Kg Lb Kg lb Kg lb Cement Water Fines Coarse Pellet MIX The amount of water to be included in the mix was determined by using the slump test established by American Society for Testing Material (ASTM) C143/C143M Standard Test Method for Slump of Hydraulic-Cement Concrete. The standard s allowed range is between 200 to 280 mm (8 and 11 inches) [4]. Once the amount of water for the control group was established, this same amount was used in all of the groups so as to keep all materials quantities constant except for the pellets. Using the same amount of water across all groups could create a problem with the results of the slump tests because the pellets did not absorb any water. 8

25 3.2 Specimen Construction This section will cover how the specimens were mixed according to the American Society of Testing and Materials (ASTM) standards. The ASTM standards which were used in the experiment and how they were used will also be discussed. ASTM C476 Standard Specification for Grout for Masonry specifies how to mix the materials together as well as proper mixing time. The cementitious materials and aggregates, including the pellets, were mixed in the mechanical mixer for five minutes with the water to achieve the desirable consistency [5]. The mechanical mixer that was used is shown below in Figure 2. Figure 2 - Mechanical Mixer An average of ten specimens was created using the ASTM C1019 Standard Test Method for Sampling and Testing Grout [6]. A numbering method was established to minimize the possibility of specimen misidentification. The weights of the sand, gravel, water, cementitious materials and pellets used in each group are shown in Table 1 along with the corresponding identification numbers for each sample group. 9

26 The slump was measured following ASTM C143/C143M Standard Test Method for Slump of Hydraulic-Cement Concrete [4]. The presence of the pellets in the mixtures increased the slump results since the pellets do not absorb any water and the amount of water in the mixture remained unchanged from the control group. The control mix, containing 100% of coarse aggregate, was targeted to a slump of 200 mm (8 inches). The apparatus used for the slump test is shown in Figure 3. ASTM C172 Standard Practice for Sampling Freshly Mixed Concrete was followed to determine which samples from the batches were chosen [7]. The sample for the slump could not be obtained from the first and final portions of the mixture. The slump mold was filled in three portions of approximately equal height, rodding each layer 25 times uniformly over the cross section, penetrating approximately 25 mm (1 inch) in the layer below. The mold was removed immediately in a vertical position without twisting, in about 5 to 7 seconds. The slump was measured by the distance between the top of the mold and the displaced center of the top surface of the specimen. The temperature was measured following ASTM C1064/C1064M Standard Test Method for Temperature of Freshly Mixed Hydraulic- Cement Concrete [8]. The records of the slump and temperatures for the experiment are shown in Table 2. Table 2 Temperature and Slump Temperature Slump Group C F Mm in

27 Figure 3 Slump Apparatus The mold cell was filled according to specifications in ASTM C1019. First, the mold was filled within 15 minutes of obtaining the final portion of the sample. Additionally, the mold was filled in two layers of equal parts, rodding 15 times for each layer. The second layer was rodded by penetrating the first layer where strokes were distributed evenly over the cross section and then the top surface was straightedge to produce a flat surface [6]. After 24 hours, the specimen was removed from the mold. To identify each group a number was painted on each specimen before it was placed in the moist room, as shown in Figures 4 and 5. Once numbered, the specimens were placed in a moist room of 100% humidity until the day of testing, where they stayed until capping and testing. Figure 4 - Identifying Specimens 11

28 Figure 5 Group of Specimens 3.3 Specimen Testing The first procedure to test the specimens was capping. ASTM C1552 Standard Practice for Capping Concrete Masonry Units, Related Units and Masonry Prism for Compression Testing was followed to cap the specimens [9]. Sulfur was the material used to cap the specimens. Before the capping procedure, the specimens were removed from the moist room and allowed to dry for one hour. Both ends of the specimens were capped in order to have a flat surface (Figure 5 and 6).. Figure 6 - Capping 12

29 Figure 7 - Sulfur used for capping The compressive strength test was conducted using the specifications of ASTM C-1019 and ASTM C39 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens [10]. Pictures were taken of the specimens at this stage and can be found in Appendix A. Once the capping process was complete, each group of specimens was numbered one to eleven, in order to create a unique identifier for each specimen in the experiment. The numbers seven and twenty-eight at the beginning show the day that it was tested. The second number shows to which group the specimen belong. The last number is the specimen number for that specific group. 13

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31 4 OBSERVATION AND RESULTS 4.1 Overview This section will present the results from the compression test performed on the grout specimens. The documentation to support the results will be presented as needed. The exclusion or slight modification of data will be discussed as necessary. Graphs showing all the compressive stress vs. displacement curve for the each group are included here. A statistical analysis was also done to determine how different/similar the modified groups were from the control group. Shown in Figures 8 and 9, water came out of the mixture and rose to the surface or leaked out of the molds. Figure 8 - Leaking on the top 15

32 Figure 9 - Leaking on the floor 4.2 Results All of the stress test results were collected and then each sample was individually graphed by group, as seen Figures 10 to 19. Tables 3 through 6 summarize the maximum stress for each specimen (Tables 3, 4, 5 and 6). 16

33 Stress (psi) Group 1 (Control) Deformation (in) 7,1,1 7,1,2 7,1,3 7,1,4 7,1,5 7,1,6 7,1,7 7,1,8 7,1,9 7,1,10 7,1,11 Figure 10 - Stress versus Deformation for 7 Days for Group 1 Stress (psi) Group 2 (5%) Deformation (in) 7,2,1 7,2,2 7,2,3 7,2,4 7,2,5 7,2,6 7,2,7 7,2,8 7,2,9 7,2,10 7,2,11 Figure 11 - Stress versus Deformation for 7 Days for Group 2 17

34 Stress (psi) Group 3 (10%) Deformation (in) 7,3,1 7,3,2 7,3,3 7,3,4 7,3,5 7,3,6 7,3,7 7,3,8 7,3,9 7,3,10 7,3,11 Figure 12 - Stress versus Deformation for 7 Days for Group 3 Stress (psi) Group 4 (15%) Deformation (in) 7,4,1 7,4,2 7,4,3 7,4,4 7,4,5 7,4,6 7,4,7 7,4,8 7,4,9 7,4,10 7,4,11 Figure 13 - Stress versus Deformation for 7 Days for Group 4 18

35 Stress (in) Group 5 (20%) Deformation (in) 7,5,1 7,5,2 7,5,3 7,5,4 7,5,5 7,5,6 7,5,7 7,5,8 7,5,9 7,5,10 Figure 14 - Stress versus Deformation for 7 Days for Group 5 Stress (psi) Group 1 (Control) Deformation (in) 28,1,1 28,1,2 28,1,3 28,1,4 28,1,5 28,1,6 28,1,7 28,1,8 28,1,9 28,1,10 28,1,11 Figure 15 - Stress versus Deformation for 28 Days for Group 1 19

36 Stress (psi) Group 2 (5%) Deformation (in) 28,2,1 28,2,2 28,2,3 28,2,4 28,2,5 28,2,6 28,2,7 28,2,8 28,3,9 28,2,10 28,2,11 Figure 16 - Stress versus Deformation for 28 Days for Group 2 Stress (psi) Group 3 (10%) Deformation (in) 28,3,1 28,3,2 28,3,3 28,3,4 28,3,5 28,3,6 28,3,7 28,3,8 28,3,9 28,3,10 28,3,11 Figure 17 - Stress versus Deformation for 28 Days for Group 3 20

37 Stress (in) Group 4 (15%) Deformation (in) 28,4,1 28,4,2 28,4,3 28,4,4 28,4,5 28,4,6 28,4,7 28,4,8 28,4,9 28,4,10 28,4,11 Figure 18 - Stress versus Deformation for 28 Days for Group 4 Stress (psi) Group 5 (20%) Deformation (in) 28,5,1 28,5,2 28,5,3 28,5,4 28,5,5 28,5,6 28,5,7 28,5,8 28,5,9 28,5,10 28,5,11 Figure 19- Stress versus Deformation for 28 Days for Group 5 21

38 Table 3 Group 1 and 2 Max. Stress at 7 days Spec. Max Stress Spec. Max Stress # Mpa psi # Mpa Psi 7,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, Table 4 Group 3, 4 and 5 Max. Stress at 7 days Spec. Max Stress Spec. Max Stress Spec. Max Stress # Mpa psi # Mpa psi # Mpa psi 7,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, * * * *Only 10 specimens were tested for group 5 22

39 Table 5 Group 1 and 2 Max. Stress at 28 days Max Stress Max Stress Spec. # Mpa psi Spec. # Mpa Psi 28,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, ,1, ,2, Table 6 Group 3, 4 and 5 Max. Stress at 28 days Max Stress Max Stress Max Stress Spec. # Mpa psi Spec. # Mpa psi Spec. # Mpa psi 28,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, ,3, ,4, ,5, Data Treatment A statistical analysis was performed to determine the significance of each group relative to the control group. Compression test data were collected on two different days, being either seven or twenty-eight days, using a Baldwin machine and the Instron Blue Hill software package. Since 23

40 each sample group contained twenty or more specimens, a minimum of ten samples were broken on either date as part of the compression test. The data gathered from the compression test was the load applied by the machine that caused a given sample to break. This data was then converted to a compressive stress by dividing by the cross-sectional area of the cylinder so that the results could be better analyzed and shown more easily. Outliers were identified and excluded based on the reasoning that there was a break down in the casting process for those respective samples. The variance of the outliers to the rest of the specimen group can be seen in Figure 20 through 23. The horizontal axis arrangement matches the output of the variance from the software, thus the non-standard arrangement. Figure 20 - Box plot from 7 days with outlier Figure 21 - Box plot from 7 days without outlier 24

41 Figure 22 - Box plot from 28 days with outlier Figure 23 - Box plot from 28 days without outlier Two different analyses were conducted, one with specimens at seven days and another one with the specimens at 28 days. The program used to analyze the data was JMP and an analysis of variance (ANOVA) was conducted to compare the PET variable sample groups to the control group. 25

42 4.3.1 Statistical Analysis at Day 7 The specimens used in this analysis had cured for 7 days. Two outlier samples were eliminated from the analysis, those being specimen number ten from group 5 and specimen number 1 from group four. They were eliminated because their results indicated a break down in the process and consequently caused large changes to the results in the statistical analysis. There are two factors that could cause the break down. First, the water that leaked from the specimens on the first day. Second, the amount of mix was just enough to fill the molds; in some cases there was a need to scrape the wheelbarrow in other to fill the mold. In these cases these specimens could have had more fines than the other specimen. It is possible to see the difference with and without the outliers comparing the box plots in Figure 20 and 21. From the analysis of variance (Table 7) we can see that the p-value, called Prob>F in this table, is less than 0.05, thereby showing the existence of significant difference between the groups. The analysis shows that the results for two of the modified groups, groups two and five, are not different from the control group. On the other hand, groups three and four are statistically significant difference between them and the control group (Table 8 and Figure 24). Table 7 Analysis of variance table for 7 days Analysis of Variance Source DF Sum of Squares Mean of Squares F Ratio Prob > F Model Error C. Total

43 Table 8 Difference from the control for 7 days LSMeans Differences Hsu-Dunnett α=0.05 Q= Control=Control Level Level Difference Std Err Dif Lower CL Upper CL p- value 5% Control % Control % Control % Control Figure 24 - Difference from the control for 7 days Statistical Analysis for Day 28 The specimens used in this analysis had cured for 28 days. One outlier was eliminated from the analysis, specimen number eight from group four. It was eliminated because the result indicated a break down in the process and consequently caused large changes to the results in the statistical analysis. There are two factors that could cause the break down. First, the water that leaked from the specimens on the first day. Second, the amount of mix was just enough to fill the molds; in some cases there was a need to scrape the wheelbarrow in other to fill the mold. In these cases these specimens could have had more sand than the other specimens. It is possible to see the difference with and without the outliers comparing the box plots in Figure 22 and

44 From the analysis of variance (Table 9) we can see that the p-value, called Prob>F in this table, is less than 0.05, thereby showing the existence of significant difference between the groups. The analysis shows that the results for two of the modified groups, groups three and five, are not different from the control group. On the other hand, groups two and four show a statistical difference between them and the control group (Table 10 and Figure 25). Table 9 Analysis of variance table for 28 days Analysis of Variance Mean Source DF Sum of Squares of Squares F Ratio Prob > F Model Error C. Total Table 10 Difference from the control for 28 days LSMeans Differences Hsu-Dunnett α=0.05 Q= Control=Control Level Level Difference Std Err Dif Lower CL Upper CL p- value 5% Control % Control % Control % Control

45 Figure 25 - Difference from the control for 28 days Theoretically, all mixes with PET should be or should not be statistically different; in other words, the results should have been consistent. As mentioned above, significant bleeding was observed, which unfortunately was not monitored. Thus, it is unknown which specimen and group lost more water. Such loss decreased the water-cement ratio and most likely increased the compressive strength. Another factor that may have affected the results is that the groups were not made on the same day. More research, therefore, is needed to determine the actual reason of the non-consistent behavior. Despite the differences, one mix being statistically different while another is not, the mixes with PET has overall similar results to that of the control group indicating that PET did not cause a reduction on the compressive strength. Practically, all the mixes had results that achieve the ASTM standard. Table 11 summarizes the gain in compressive strength from the 7-day break to the 28-day break for all groups. 29

46 Table 11 Increase in Compressive Strength Group Median Compressive Strength (psi) 7 Days 28 Days Increase (%) Control % % % % With exception of the group with 10% of PET, the increase in strength was 50% or greater. Also, all PET mixes, except that with 10% experienced gains similar to that experienced by the control mix. As mentioned above, the bleeding water, the slightly different mixing conditions, and the scrapping of the wheelbarrow to fill the mold may have influenced the results. Unfortunately, researchers are not able to quantify the influence of these variables. In this research, the comprehensive strength of them mixes was the main focus. Nevertheless, deformation is also important. Further research and analysis are needed to determine how deformation of the different mixes affects the results presented herein. 30

47 5 CONCLUSION The grout experiment replacing coarse aggregate with PET material had significant results that showed PET as a suitable substitute in a grout compound. The samples using PET showed the same or greater ultimate compressive strength as the control group. The statistical analysis showed that at 7-day, the groups with 10% and 15% are significant different than the control group. The difference in mean strength are 320 and 339 psi, respectively. At 28 day, the groups with 5% and 15% are significant different than the control and the difference in mean strength are 338 and 392 psi, respectively. Although statistically these averages are different, in practice, the differences are most likely acceptable, especially since all grouts achieved the minimum strength specified by ASTM. Some suggestions are made below for further research. To help the statistical analysis, make two or more batches of each group in order to determine the variability, if any, between batch-to-batch. Test specimen at high temperature to determine the deterioration on the capacity due to melting or softening of the pellets. Use Concrete Masonry Units (CMU) as specified by ASTM to cast the specimens to determine if the findings of this research are maintained. Test the compressive strength of the pellets. 31

48 Lastly, compare the costs of the course aggregate and the PET pellets to determine what would be cheaper to use. The overall cost of each mix design was not calculated; however, the cost of the pellets was higher than the cost of the coarse aggregate for the study. This begs the question, How much is someone willing to pay to have a more eco-friendly designed building? 32

49 REFERENCES 1. Siddique, R., Khatib, J.and Kaur, I. (2007). Use of Recycled Plastic in Concrete: A Review. Available from: 2. Akçaözoğlu, S., Atis, C. D. and Akçaözoğlu, K. (2010) An Investigation on the Use of Shredded Waste PET Bottles as Aggregate in Lightweight Concrete ; Available from: 3. Scott, M. W. (2011) Strenght of Concrete Masonry Prisms Constructed with Non- Traditional grout and Type-M Mortar, M.S. Thesis, Brigham Young University, Provo, UT 4. ASTM Standard C143/C143M-10, Standard Test Method for Slump of Hydraulic-Cement Concrete ASTM International, West Conshohocken, PA, DOI: /C0143_C0143M, 5. ASTM C476-09, Standard Specification for Grout for Masonry, ASTM International, West Conshohocken, PA, DOI: /C , 6. ASTM C , Standard Test Method for Sampling and Testing Grout, ASTM International, West Conshohocken, PA, DOI: /C , 7. ASTM C172-08, Standard Practice for Sampling Freshly Mixed Concrete, ASTM International, West Conshohocken, PA, DOI: /C , 8. ASTM C1064/C1064M-08, Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete, ASTM International, West Conshohocken, PA, DOI: /C1064_C1064M-08, 9. ASTM C a, Standard Practice for capping Concrete Masonry Units, Related Units and Masonry Prism for Compression Testing, ASTM International, West Conshohocken, PA, DOI: /C A, ASTM C39/C39M-09a, Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, ASTM International, West Conshohocken, PA, DOI: /C0039_C0039M-09a, 33

50 11. Masonry Society s (2010), Masonry Designers Guide, 6 th edition 12. Bayasi, Z., Zeng, J. (1993), Properties of Polypropylene Fiber Reinforced Concrete, ACI Materials Journal Silva, D.A., Betiloli, A.M., Gleize, P.J.P., Roman, H.R, Gomez, L.A., Ribeiro, J.L.D (2005), Degradation of Recycled PET Fibers in Portland Cement-based Materials, Available from: Ochi, T., Okubo, S. and Fukui, K. (2007), Development of Recycled PET fiber and its application as Concrete-reinforce Fiber, Available from: 34

51 APPENDIX A. PICTURES Figure 26 Spec. 7,1,1 Figure 27 Spec. 7,1,2 Figure 28 Spec. 7,1,3 Figure 29 Spec. 7,1,4 35

52 Figure 30 Spec. 7,1,5 Figure 31 Spec. 7,1,6 Figure 32 Spec. 7,1,7 Figure 33 Spec. 7,1,8 Figure 34 Spec. 7,1,9 Figure 35 Spec. 7,1,10 36

53 Figure 36 Spec. 7,1,11 Figure 37 Spec. 7,2,1 Figure 38 Spec. 7,2,2 Figure 39 Spec. 7,2,3 Figure 40 Spec. 7,2,4 Figure 41 Spec. 7,2,5 37

54 Figure 42 Spec. 7,2,6 Figure 43 Spec. 7,2,7 Figure 44 Spec. 7,2,8 Figure 45 Spec. 7,2,9 Figure 46 Spec. 7,2,10 Figure 47 Spec. 7,2,11 38

55 Figure 48 Spec. 7,3,1 Figure 49 Spec. 7,3,2 Figure 50 Spec. 7,3,3 Figure 51 Spec. 7,3,4 Figure 52 Spec. 7,3,5 Figure 53 Spec. 7,3,6 39

56 Figure 54 Spec. 7,3,7 Figure 55 Spec. 7,3,8 Figure 56 Spec. 7,3,9 Figure 57 Spec. 7,3,10 Figure 58 Spec. 7,3,11 Figure 59 Spec. 7,4,1 40

57 Figure 60 Spec. 7,4,2 Figure 61 Spec. 7,4,3 Figure 62 Spec. 7,4,4 Figure 63 Spec. 7,4,5 Figure 64 Spec. 7,4,6 Figure 65 Spec. 7,4,7 41

58 Figure 66 Spec. 7,4,8 Figure 67 Spec. 7,4,9 Figure 68 Spec. 7,4,10 Figure 69 Spec. 7,4,11 Figure 70 Spec. 7,5,1 Figure 71 Spec. 7,5,2 42

59 Figure 72 Spec. 7,5,3 Figure 73 Spec. 7,5,4 Figure 74 Spec. 7,5,5 Figure 75 Spec. 7,5,6 Figure 76 Spec. 7,5,7 Figure 77 Spec. 7,5,8 43

60 Figure 78 Spec. 7,5,9 Figure 79 Spec. 7,5,10 Figure 80 Spec. 28,1,1 Figure 81 Spec. 28,1,2 Figure 82 Spec. 28,1,3 Figure 83 Spec. 28,1,4 44

61 Figure 84 Spec. 28,1,5 Figure 85 Spec. 28,1,6 Figure 86 Spec. 28,1,7 Figure 87 Spec. 28,1,8 Figure 88 Spec. 28,1,9 Figure 89 Spec. 28,1,10 45

62 Figure 90 Spec. 28,1,11 Figure 91 Spec. 28,2,1 Figure 92 Spec. 28,2,2 Figure 93 Spec. 28,2,3 Figure 94 Spec. 28,2,4 Figure 95 Spec. 28,2,5 46

63 Figure 96 Spec. 28,2,6 Figure 97 Spec. 28,2,7 Figure 98 Spec. 28,2,8 Figure 99 Spec. 28,2,9 Figure 100 Spec. 28,2,10 Figure 101 Spec. 28,2,11 47

64 Figure 102 Spec. 28,3,1 Figure 103 Spec. 28,3,2 Figure 104 Spec. 28,3,3 Figure 105 Spec. 28,3,4 Figure 106 Spec. 28,3,5 Figure 107 Spec. 28,3,6 48

65 Figure 108 Spec. 28,3,7 Figure 109 Spec. 28,3,8 Figure 110 Spec. 28,3,9 Figure 111 Spec. 28,3,10 Figure 112 Spec. 28,3,11 Figure 113 Spec. 28,4,1 49

66 Figure 114 Spec. 28,4,2 Figure 115 Spec. 28,4,3 Figure 116 Spec. 28,4,4 Figure 117 Spec. 28,4,5 Figure 118 Spec. 28,4,6 Figure 119 Spec. 28,4,7 50

67 Figure 120 Spec. 28,4,8 Figure 121 Spec. 28,4,9 Figure 122 Spec. 28,4,10 Figure 123 Spec. 28,4,11 Figure 124 Spec. 28,5,1 Figure 125 Spec. 28,5,2 51

68 Figure 126 Spec. 28,5,3 Figure 127 Spec. 28,5,4 Figure 128 Spec. 28,5,5 Figure 129 Spec. 28,5,6 Figure 130 Spec. 28,5,7 Figure 131 Spec. 28,5,8 52

69 Figure 132 Spec. 28,5,9 Figure 133 Spec. 28,5,10 Figure 134 Spec. 28,5,11 53