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From page 1... ... 1 Background Cement kiln dust (CKD) is generated during the production of the cement clinker and is a dust particulate mixture of partially calcined and unreacted raw feed, clinker dust, and ash, enriched with alkali sulfates, halides, and other volatiles (Adaska and Taubert 2008) Read the entire page →
From page 2... ... 2 Fresh cement kiln dust Properties Recent and extensive data on CKD chemistry was reported by Williams (2005) for a project that included an in-depth analysis of cement producers scattered throughout the United States and Canada. Read the entire page →
From page 3... ... 3 Constituent % by Weight Long-wet kiln Long-dry kiln Alkali by -pass from preheater/precalciner Typical type I ce me nt Si O 2 15.02 9.694 15.23 20.5 Al 2 O 3 3.8 3.39 3.07 5.4 Fe 2 O 3 1.88 1.1 25 2.6 CaO 41.01 44.91 61.28 63.9 MgO 1.47 1.29 2.13 2.1 SO 3 6.27 6.74 8.67 3 Na 2 SO 4 0.74 0.27 0.34 <1 K 2 O 2.57 2.4 2.51 <1 Loss on Ignition 25.78 30.24 4.48 0–3 Free Li me (CaO) 0.85 0.52 27.18 <2 Todres et al. Read the entire page →
From page 4... ... 4 less than 10% for seven compounds, and all but two were below 27%. There was also reasonably low variation between properties initially reported by the plant, those reported by the plant at the time of sampling, and those found when tested by an independent third party (Table 5) Read the entire page →
From page 5... ... ID Sample Date Percent by Total Weight, % CaO Si O 2 Al 2 O 3 Fe 2 O 3 MgO SO 3 Na 2 O K 2 O Ti O 2 P 2 O 5 SrO Mn 2 O 3 LOI LH Quoted 9/04 41.93 12.66 3.17 0.78 1.75 6.15 0.4 9.71 NR NR NR NR 23.44 Received 2/05 38.56 15.46 1.77 1.25 1.3 4.23 0.27 7.62 NR NR NR NR 28.24 Tested 7/05 39.01 12.58 4.45 2.28 1.7 7.46 0.29 10.96 0.17 0.08 0.06 NR 25.9 HH Quoted 12/04 65.55 13.9 4.95 1.92 1.37 5.26 0.39 6.42 0.22 0.09 0.02 0.05 35.41 Received 2/05 70.25 14.75 5.14 1.89 1.47 2.64 0.17 2.51 0.23 0.08 0.02 0.04 35.26 Tested 7/05 51.94 10.62 3.94 2.68 1.02 2.26 0 1.87 0.19 0.03 2 NR 35.28 HL Quoted 9/04 62.09 17.62 4.9 2.58 1.93 5.79 0.56 3.76 NR NR NR NR 4.94 Received 3/05 51.94 13.27 4.04 1.97 1.55 3.79 0.57 6.13 0.28 0.09 0.11 NR 9.87 Tested 7/05 44.64 13.35 3.83 2.57 2.44 3.64 0.8 5.46 0.19 0.05 0 NR 8.07 LL Quoted 5/04 47.75 15.16 4.56 1.84 2.09 10.15 0.99 9.81 NR NR NR NR 1.77 Received 4/05 47.47 14.11 4.3 1.82 1.96 13.35 0.94 9.74 NR NR NR NR NR Tested 7/05 38.89 13.43 3.86 2.25 1.99 13.85 1.36 8.77 0.15 0.11 0.04 0 1.4 After Williams (2005) Read the entire page →
From page 6... ... 6 CKD were relatively consistent throughout the 12 years of the operation, although there were noticeable differences in the composition as a result of hydration over time. usage and Production As of 2006, fewer than 20 of the 118 cement plants in the United States managed 90% of the CKD disposed on-site (Adaska and Tauber 2008; PCA 2008) Read the entire page →
From page 7... ... 7 can be seen in Figure 4. The clinker production quantity increased significantly from 1990 to 2006; however, the amount of CKD landfilled significantly decreased over the same time. Read the entire page →
From page 8... ... 8 cement kiln dust regulatory history Adaska and Taubert (2008) provided the history of legislation in the United States for the regulation of CKD byproducts. Read the entire page →
From page 9... ... 9 activities. Water is considered a valuable commodity in Oman and using contaminated water in construction projects reduces the demand for fresh water. Read the entire page →
From page 10... ... 10 and between 780 and 1,380 for the HH and LL pastes (the high and low level of LOI) Read the entire page →
From page 11... ... 11 Mix CKD:Fly Ash w:cm Bleeding, % Flowability Unit Weight, pcf Inverted slump cone ASTM D6130 in. Read the entire page →
From page 12... ... 12 ID CKD:Fly Ash Indentation after Various Times, inches 24 hours 48 hours 72 hours 96 hours LH 5:15 3.5 3.4 -- -- 10:10 3.9 3.5 -- 3.1 15:5 -- -- 4.5 -- 20:0 -- -- 2.9 -- HH 5:15 -- 4 3.5 3.1 10:10 -- -- 3.5 -- 15:5 -- -- -- -- 20:0 -- 3.1 2.5 -- HL 5:15 -- 2.8 2.0 -- 10:10 -- -- 2.8 2.5 15:5 -- -- 3.4 3 20:0 -- -- 4.0 -- LL 5:15 -- -- 3.6 -- 10:10 -- -- 4.0 -- 15:5 -- -- 4.25 -- 20:0 -- -- 4.25 -- After Williams (2005) Read the entire page →
From page 13... ... 13 The change in CLSM sample volume was also evaluated (Table 18) Read the entire page →
From page 14... ... 14 minimum value needed for either the wear or binder courses. The VMA was similar to the control mix, which also did not meet the specification; however, it is not clear that these are statistically significant. Read the entire page →
From page 15... ... 15 The selection of treatment depends on the specific goals for a specific project, soil type, material availability, traffic loads, pavement design needs, environmental conditions (e.g., drainage, ground water table, and precipitation) , and costs. Read the entire page →
From page 16... ... 16 Testing focused on determining the resilient modulus values for the mixtures since this material property is used in mechanistic-empirical pavement design methods. Results were dependent on the particular combination of stabilizing material and aggregate source (Table 24) Read the entire page →
From page 17... ... Stresses Resilient Modulus, ksi for 15% CKD tsemiL 1 enotsemiL enotsdnaS 2 eno Aggregate: 97% CaO3 0.9 to 1.2% MgO3 0.25 to 6.2% SiO2 34% for LA abrasion Aggregate: 87% CaCO3 -- 10% SiO2 26% for LA abrasion Aggregate: -- -- 94% SiO2 22% for LA abrasion Confining Stress, σ3 Deviator Stress, σd Seating Pressure, σs No. freeze/thaw cycles No. Read the entire page →
From page 18... ... 18 Property Precalciner Kiln Long-Kiln SiO2 0.40–1.11 26.71 % , Al2O3 0.5–5.3 9.4 % , Fe2O3 5.5–2.1 85.2 % , -- 80.26 % ,OaC -- 39.1 % ,OgM Na2 0.1–1.0 65.0 % ,O K2 0.01– 0.2 67.3 % ,O SO3 0.21–00.8 97.5 % , 0.1–3.0 -- % ,selitaloV Available Lime Index, % CaO 33.7 -- Water-Soluble Chlorides, % Cl -- -- -- 70.0 % ,tnetnoC erutsioM -- 49.4 % ,noitingI no ssoL Retained on No. 325 sieve, % 16.9 -- 57–55 -- % ,mm 570.0 gnissaP -- 59.2 ytivarG cificepS 9.21–4.21 -- Hp After Parsons et al. Read the entire page →
From page 19... ... 19 • Evaluate the sulfate in the CKD and soils. Soils or CKD materials with sulfates could potentially react with free lime and form expansive minerals, resulting in additional swelling where none previously existed. Read the entire page →
From page 20... ... 20 cement plant, had a lower free lime content that resulted in poor reactivity. Peethamparan et al. Read the entire page →
From page 21... ... 21 • CKD can be used to stabilize subgrade soils and bases; the combination of CKD and fly ash significantly increase the compressive strength because of the pozzolanic reactions. • High-quality bases for pavements can be obtained using CKD, but testing is needed to optimize the performance. Read the entire page →
From page 22... ... 22 CKD recycling was used by a majority of the cement producers. Although a number of plants could reuse 100% of their CKD, the amount that was recycled ultimately depended on the chemistry of the CKD. Read the entire page →
From page 23... ... 23 lization (Table 33) Read the entire page →
From page 24... ... 24 tnemmoC etatS CO Cement kiln dust did not perform well in the soil we were trying to stabilize. KY Kiln dust used for soil stabilization can be successful, but it depends on the type of soil involved (critical) Read the entire page →
From page 25... ... 25 materials handling issues The following materials handling and stockpiling points need to be considered: • CKD byproduct could designate the type of kiln that generated the byproduct. • Age of stockpiles needs to be tracked and the age of the CKD be included in the byproduct information provided to the user of the byproduct. Read the entire page →
From page 26... ... 26 eltiT dohteM MTSA C204 Standard Test Methods for Fineness of Hydraulic Cement by Air-Permeability Apparatus C403 Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance D1633 Standard Test Methods for Compressive Strength of Molded Soil-Cement Cylinders D1833 Standard Test Method for CBR of Laboratory Compacted Soils D2487 Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System) D422 Standard Test Method for Particle Size Analysis of Soils D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils D4647 Standard Test Method for Identification and Classification of Dispersive Clay Soils by the Pinhole Test D5050 Standard Guide for Commercial Use of Lime Kiln Dusts and Portland Cement Kiln Dusts D5102 Standard Test Method for Unconfined Compressive Strength of Compacted Soil-Lime Mixtures D5120 Standard Test Method for Inhibition of Respiration in Microbial Cultures in the Activated Sludge Process D560 Standard Test Methods for Freezing and Thawing Compacted Soil-Cement Mixtures D6023 Standard Test Method for Density (Unit Weight) Read the entire page →

From page 1...

... 1 Background Cement kiln dust (CKD) is generated during the production of the cement clinker and is a dust particulate mixture of partially calcined and unreacted raw feed, clinker dust, and ash, enriched with alkali sulfates, halides, and other volatiles (Adaska and Taubert 2008)