THE DEVELOPMENT OF BEHAVIOR MODEL OF SOIL CEMENT MIXTURE AS A RESULT OF A DYNAMIC TRAFFIC LOAD USING FLY ASH AND TIMOR SOIL (EAST NUSA TENGGARA)

• Main Author: THEODORUS (NIM : 35006002), ALFONSUS
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/14804
• Institution: Institut Teknologi Bandung

Soil cement mixture is a mixture of soil with cement and water, which undergoes a compaction method that produces a new structural material. This soil cement, because of its strength, durability characteristics towards water, heat, weather and others, is really good for hardening road foundation. Fly Ash as an alternative of road material can be used as an additional material to the mixture of soil cement. <br /> <br /> <br /> The test was conducted by using Oelamasi Soil and Bolok Soil, both are from East Nusa Tenggara, with Fly Ash from Suralaya. <br /> <br /> <br /> The test of the strength of this soil cement mixture is usually carried out under the static and dynamic loadings. The terminology for dynamic loading is for simulating the condition at the field where the actual traffic is a dynamic load. <br /> <br /> <br /> The research was conducted under several stages, such as static stage that accommodates static test like UCS. Dynamic test such as Fatigue Test was also carried out. The result of the test shows that Oelmasi Soil can be classified as a high plasticity non-organic clay (CH) with its clay type A-7-5, Activity Value (A)=1,30 (Active Clays) and it has a very high Swelling Potency as well as it <br /> <br /> <br /> contains a high Quartz Mineral. <br /> <br /> <br /> In general, 5% - 15% cement shows optimum amount reduction of Plasticity Index (PI). While 3% - 7% fly ash can reduce the value of Plasticity Index (PI). The addition or reduction of Plasticity Index is an indicator of strength changes from TO/CH. The addition of 15% cement at curing of 28 days has optimal value of Unconfined Compressive Strength (UCS) = 18,7 Kg/Cm2 with a Correlation Model UCS28 Days = f (-27,5923 + 3,0856KS), S28 Days = f (28,7168 – <br /> <br /> <br /> 1,2548KS) meanwhile with the addition of 15% fly ash reaches the value of 1,610 Kg/Cm2 with Correlation Model UCS28 Days = f (- 2,0755+0,2511KFA), S28 Days = f (34,993 – 2,0334KFA). The value of Permeability of the soil mixture of CH and 15 % fly ash (K= 0.00004 cm/sec) is less than the soil mixture of TO/CH and 15% cement (K= 0.00047 cm/sec) at the curing age of 28 days. The result of observation shows that the higher the content of the cement is, the lower the <br /> <br /> <br /> permeability will be. <br /> <br /> <br /> Bolok Soil (TB/SW) with the content of Mineral Calcite. The addition of 10% cement can increase the value of UCS to its optimal value 21,87 Kg/cm2 at the curing age of 28 days with Correlation Model UCS28 Days = f (5,2541 + 1,6120KS), S28 Days = f (39,2311 – 3,4807KS) meanwhile with the addition of 10% fly ash can reach the value 1,721 Kg/Cm2 with Correlation Model UCS28 Days = f (0,9082 + 0,0813KFA). <br /> <br /> <br /> The permeability value of the mixture of Bolok soil and 10% cement (K=0.0005cm/sec) is bigger than that of the mixture of oelmasi soil and fly ash (K=0.00022 cm/sec) at the 28 days burial. The result of observation also shows that <br /> <br /> <br /> the higher the content of the cement is, the lower the permeabiltity will be. <br /> <br /> <br /> For the mixture of 75% Bolok Soil and 25% Oelamasi Soil, the PI obtained is 13,23% which is classified as Sands Clay (A-2-6) or Mixture Soil (TC/SC). The addition of 12% cement can increase the value of UCS up to its optimum value <br /> <br /> <br /> 18.501 kg/cm2 at the curing age of 28 days with Correlation Model UCS28 Days = f (-16,5219 + 2,9109KS), S28 Days = f (15,6448 – 1,0647KS) while the addition of 12% fly ash reaches the value of 6.282 Kg/Cm2 with Correlation Model UCS28 Days= f (-1,9607 + 0,7116KFA) The permeability value of Mixture Soil (TC/SC) and 9% cement ( K= 0,002790 <br /> <br /> <br /> cm/sec) is bigger than TO/CH and fly ash (K= 0,000084 cm/sec) at 14 days burial. <br /> <br /> <br /> The observation result also shows the higher the The result of observation also shows that the higher the content of the cement is, the lower the permeabiltity will be. <br /> <br /> <br /> At the Fatigue Test with the Curing Age of 28 days, the stress variation started at 0,2kN. The test started with the load of 0,2kN with the addition of stress 0.025 kN <br /> <br /> <br /> (for each 3000 cycle). Each underwent a failure at 31.293, 30.014, 27.085 cycle with each deflection (&#948;f) = 0,0845 mm, 0,0853 mm and 0,0763 mm repectively. <br /> <br /> <br /> The modulus value of the final stiffness of TB/SW with 10% cement increased in line with the curing age. The average modulus value of final stiffness Eaverage from the fatigue test for the curing age of 7 days, 14 days, 21 days and 28 days is 4.030 MPa, 4.198 MPa, 4.460 MPa dan 4.665 MPa respectively with Correlation Model Ef = 30,942UP+ 3796,9, Nf = 19,674 Ef - 62.060. <br /> <br /> <br /> On its application, in pavement structure design for road the result of a calculation according to AASHTO’93 is : Layer of Base Soil Cement ( Bolok Soil/ SW and 10% cement) has Load Equivalency Factor (Load ESALS/W18) that is the same if compared with the plan of using Crushed Stone as a Foundation. Thus, Soil Cement can replace Crushed Stone as the base. <br /> <br /> <br /> The calculation of this &#916;NPV states that the use of Soil Cement TB/SW as the foundation layer with the surface layer of lataston HRS – WC 5 cm width has lower cost compared with the use of Class A aggregate with the surface layer of <br /> <br /> <br /> HRS – WC 5 cm width. <br /> <br /> <br /> For further study Fatigue Test can be conducted for TO/CH and TC/SC.