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21 Table 3.5. Additional CLSM mixtures. Cement Fly Ash Water Total Air Fresh Fly Ash Fine Aggregate Flow Mixture Content Content Demand Bleeding Content Density Type b Type c (cm) (kg/m 3 ) (kg/m 3 ) (kg/m 3 ) (%) (%) (kg/m 3 ) 25 60 HC 1200 None 853 24.0 7.38 1.3 1322 27 60 F 1200 None 486 23.0 1.28 0.7 1638 28 a 60 F 180 CSd 220 20.0 1.33 1.4 2182 29 a 60 None 0 FSd 373 23.0 0.28 2.6 1812 24 60 F 1200 None 486 24.0 2.25 2.8 1635 30 a 30 None 0 FSd 414 20.0 0.40 2.0 1789 26 a 60 None 0 CSd 136 16.5 0.00 25.5 1802 a Mixtures contain accelerating admixture. b HC = High Carbon, F = Class F c CS = Concrete Sand, FS = Foundry Sand d Fine aggregate content was held constant at 1500 kg/m3. hardened property measured), the research team placed par- Testing Program ticular emphasis on developing a refined test that is more re- liable and reproducible. Issues such as load rate, curing condi- Overview tion, temperature effects, and capping methods were studied This section provides information on the test methods in detail. The development of an improved compressive used. Test methods are grouped into three categories based strength test method is also critical because of the inclusion of on the characteristics that they are intended to measure; fresh strength in most specifications, especially as in relation to properties, hardened properties, and durability characteris- excavatability. tics. Some characteristics were studied in more detail than Tables 3.7 through 3.15 show the mixture proportions, others. A summary of the measured characteristics and used along with selected fresh properties, for the additional investi- methods is provided in Table 3.17. gations. To be consistent with the initial mixtures that contain aggregates, the aggregate content was held constant at 1500 Mixing Procedure kg/m3. These tables also contain some information on fresh CLSM characteristics and in some cases data are provided on Trial mixing was performed for the initial 38 mixtures to de- properties, such as compressive strength. The findings of these termine their approximate water demand for a target flow of investigations are provided in more detail later in this chapter. 200 to 250 mm. Flow was measured following ASTM D 6103. Because of relevance to field applications and based on im- After determining the quantities of water for the target flow, portant findings related to corrosion of ductile iron specimens the actual mixtures were cast and test samples were prepared. embedded in the initial 38 CLSM mixtures, an expanded and For the smaller mixture volumes, a 0.028 m3 drum mixer was detailed long-term corrosion study was performed (Phase II). used. For the larger mix volumes (needed for measuring In Phase II, additional CLSM mixtures were prepared and dif- additional characteristics on the selected mixtures), a high- ferent corrosion scenarios were evaluated. The mixture pro- capacity (0.056 to 0.070 m3) laboratory mixer was used. portions and fresh properties for the mixtures in Phase II are Mixing procedures were different for nonair-entrained shown in Table 3.16. and air-entrained mixtures. For nonair-entrained mixtures, Table 3.6. Mixture series and their descriptions. Mixture Number of Description Series Mixtures A Effects of load rate on compressive strength (Table 3.7) 7 B Effects of curing and air drying on compressive strength (Table 3.8) 2 C Long-term strength gain and excavatability (Table 3.9) 9 D Freeze-thaw resistance (Table 3.10) 11 E Alternative capping materials for compression cylinders (Table 3.11) 18 F Effects of drainage on compression cylinders (Table 3.12) 8 G Effects of storage conditions on compressive strength (Table 3.13) 10 H Effects of temperature and humidity on compressive strength (Table 3.14) 6 I Permeability and triaxial shear strength (Table 3.15) 6

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22 Table 3.7. Mixture proportions for load rate study. Cement Fly Ash Air Fly Ash Fine Aggregate Water Flow Density Mixture Content Content Content Type a Type b (kg/m 3 ) (mm) (kg/m 3 ) (kg/m 3 ) (kg/m 3 ) (%) A-1 60 None 0 CS 156 175 25.0 1739 A-2 60 F 360 FS 520 200 1.9 1755 A-3 60 F 1200 None 486 213 1.6 1620 A-4 30 C 180 CS 265 330 1.7 2161 A-5 30 C 180 CS 213 216 c 2226 A-6 60 F 1200 None 501 216 c 1635 A-7 60 None 0 CS 156 165 24.5 1740 a F = Class F, C = Class C. b CS = Concrete Sand, FS = Foundry Sand. c Too low to measure. Table 3.8. Mixture proportions for cylinder curing/conditioning study. Cement Content Fly Ash Fly Ash Content Fine Aggregate Water Flow Mixturea (kg/m 3 ) Type (kg/m 3 ) Type b (kg/m 3 ) (mm) B-1 30 Class C 180 CS 203 250 B-2 30 Class C 180 CS 189 200 a B-1 and B-2 were cast on different days and different water contents were used to obtain the desired flow. b CS = Concrete Sand. Table 3.9. Mixture proportions used for excavation boxes and companion samples. Cement Sand Content Fly Ash Content Fly Ash Water Flow Air Content Density Mixture (kg/m 3 ) (kg/m 3 ) (kg/m 3 ) Type a (kg/m 3 ) (mm) (%) (kg/m 3 ) C-1 60 None 1195 F 485 200 Entrapped 1637 C-2 0 2000 275 C 252 229 Entrapped 2148 C-3 30 1500 0 None 112 178 28.0 1642 C-4 15 1500 180 F 177 200 Entrapped 2192 C-5 30 1500 180 F 175 200 Entrapped 2158 C-6 15 1500 180 HC 224 216 Entrapped 2095 C-7 30 1500 180 HC 224 216 Entrapped 2115 C-8 15 1500 180 C 170 206 Entrapped 2190 C-9 45 1500 0 None 103 178 25.5 1652 a F = Class F, C = Class C, HC = High Carbon. Table 3.10. Mixture proportions used for freezing and thawing study. 28-Day Cement Fine Aggregate Fly Ash Water Flow Air Density Mixture Strength (kg/m 3 ) Type a Type b (kg/m 3 ) (mm) (%) (kg/m 3 ) (MPa) D-1 30 CS None 119 180 27.0 1630 0.13 D-2 30 CS F 205 200 Entrapped 2196 1.02 D-3 30 CS HC 256 229 Entrapped 2078 0.79 D-4 30 CS C 200 216 Entrapped 1980 1.47 D-7 30 FS F 425 238 Entrapped 1835 0.11 D-6 30 FS HC 481 229 Entrapped 1757 0.12 D-5 30 FS C 399 200 Entrapped 1800 0.20 D-8 30 BA F 357 200 Entrapped 1870 0.38 D-9 30 BA HC 407 200 Entrapped 1733 0.25 D-10 30 BA C 282 200 Entrapped 1896 0.53 D-11 45 CS None 96 152 30.0 1569 0.34 a CS = Concrete Sand, FS = Foundry Sand, BA = Bottom Ash. Fine aggregate content was 1500 kg/m3. b F = Class F, HC = High Carbon, C = Class C. When included, fly ash content was 180 kg/m3

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23 Table 3.11. Mixture proportions for alternative capping materials study. Cement Fly Fly Ash Concrete Water Flow Air d Density Content Ash Content Sand Mixture (kg/m 3 ) (mm) (%) (kg/m 3 ) (kg/m 3 ) Type a (kg/m 3 ) (kg/m 3 ) E-1 60 F 1140 None 480 200 1.4 1630 E-2 None C 180 2000 250 200 1.2 1626 E-3 30 None 0 1500 109 175 29.0 1651 E-4 15 F 180 1500 184 200 1.7 1693 E-5 30 F 180 1500 176 200 2.5 2180 E-6 15 HC 180 1500 202 200 1.8 2122 E-7 30 HC 180 1500 229 225 E 2136 E-8 15 C 180 1500 179 200 1.8 2235 E-9 30 C 180 1500 238 21 E 2176 E-10 15 F 180 1500 241 19 E 2130 E-11 60 None 0 1500 153 18 29.1 1622 E-12 60 F 1200 0 500 22 E 1602 E-13 0 C 224 1672 165 19 4.0 2179 E-14 30 None 0 1500 130 20 29.5 1539 E-15 60 None 0 1500 130 22 28.5 1539 E-16 60 F 1200 0 485 42b 1.0 1795 E-17 30 F 180 1500 175 10 c 2.3 2051 E-18 60 F 180 1500 175 14 c 2.5 2083 a F= Class F, C = Class C, HC = High Carbon. b Difficult to obtain adequate flow by simply adding water. c Too much water included in the mixture. d E = Entrained. Table 3.12. Mixture proportions for drainage condition study. Cement Fly Ash Concrete Total Air Fresh Fly Ash Water Flow Content Content Sand Bleeding Content Density Mixture Type a (kg/m 3 ) (mm) (kg/m 3 ) (kg/m 3 ) (kg/m 3 ) (%) (%) b (kg/m 3 ) F-1 60 F 1140 None 480 200 2.30 1.4 1630 F-2 None C 180 2000 250 200 0.00 1.2 1626 F-3 30 None 0 1500 109 175 0.00 29.0 1651 F-4 15 F 180 1500 184 200 2.07 1.7 1693 F-5 30 F 180 1500 175 200 0.87 2170 F-6 15 HC 180 1500 224 213 2.50 2100 F-7 30 HC 180 1500 224 225 3.04 2142 F-8 15 C 180 1500 170 200 0.85 2218 a F = Class F, C = Class C, HC = High Carbon. b "" = too low to measure. Table 3.13. Mixture proportions for cylinder storage study. Fly Ash Air Cement Fly Ash Fine Aggregate Water Flow Mixture Content content c (kg/m 3 ) Type a Type b (kg/m 3 ) (mm) (kg/m 3 ) (%) G-1 60 1140 F None 485 200 E G-2 0 275 C CS 252 200 E G-3 30 0 None CS 112 187 29.0 G-4 15 180 F CS 177 200 E G-5 30 180 F CS 175 200 E G-6 45 0 None CS 103 190 30.0 G-7 30 180 F FS 349 216 E G-8 30 180 C FS 352 190 E G-9 30 180 F BA 424 140 E G-10 30 180 C BA 367 152 E a F= Class F, C = Class C. b Fine aggregate content was 1500 kg/m3. Only G-2 had 2000 kg/m3. CS = Concrete Sand, FS = Foundry Sand, BA = Bottom Ash. c E = Entrained air.