CHARACTERISTIC STUDY AND FLEXURAL-FATIGUE MODEL DEVELOPMENT OF PERVIOUS CONCRETE FROM 2-LAYER SYSTEM AS RIGID PAVEMENT BASE LAYER IN INDONESIA

• Main Author: Ridwan Aldila Melania Care, Frisky
• Format: Dissertations
• Language: Indonesia
• Subjects: Teknik sipil
• Online Access: https://digilib.itb.ac.id/gdl/view/46799
• Institution: Institut Teknologi Bandung

In the mechanistic model approach, rigid pavement is designed based on the material strength and load safety factor using two failure criteria. One of the failure criteria is fatigue failure. The fatigue failure is influenced by edge loading, subgrade support, material strength, curling stress and the number of fatigue repetition. A granular base layer frequently becomes saturated during the rain and after the rain. This saturated condition causes a movement that can decrease the base layer support. On the other hand, dense-graded base layer like lean concrete can trap water between the base layer surface and surface layer base. The appearance of repeated loading on the base layer can generate a void between the base layer surface and surface layer base (erosion). In the construction world today, concrete technology has been growing rapidly. Pervious concrete has been widely used for several purposes, especially in developing countries. Pervious concrete has high permeability and inter-connected pore so that it can allow water to surpass through. It also has an open-graded gradation and does not need too many material properties. A base layer with good drainage ability like pervious concrete was needed to tackle the erosion problem. The aim of this research was to study the pervious concrete characteristic and also developing the pervious concrete flexural-fatigue model as a rigid pavement base layer. Two main aspects that discussed were material properties performance and pavement system performance. The performance of material properties was focused on the pervious concrete gradation proportion that can fulfill the minimum criteria of base layer and drainage layer. The performance of the pavement system was focused on pervious concrete flexural-fatigue development using a 2-layer system for unbonded and bonded condition. On bonded condition, the structural capacity of pervious concrete was utilized to support the cement concrete. 2-layer system was chosen in the flexural-fatigue model development because the pervious concrete was placed as the base layer. This study was conducted using a laboratory test approach, i.e. compressive strength, void content, permeability, elastic modulus, heterogeneity level, shear strength, flexural strength, and fatigue repetition. The specimen was only focused on the variation of aggregate gradation using w/c 0.30 and a/c 4.0. The fatigue test was restricted to 1-layer and 2-layer concrete beam. The shear failure on the 2-layer beam with the bonded condition was assumed happening on the interface layer. The flexural-fatigue model development was focused on a 2-layer system. On both developed models, clogging was assumed not happening on the pervious concrete layer. The average value of pervious concrete vertical permeability with uniform and continuous gradation was + 15 higher than the minimum requirement. 1-dimension heterogeneity level with the coefficient of variance 1.8% showed that pervious concrete could give uniform support to the rigid pavement. The gradation composition of pervious concrete that consists of 3 aggregate size, i.e. 19,0 mm – 12,7 mm with percentage < 25%; 9.5 mm with percentage > 65%; 4,75 mm – 2,36 mm with percentage < 10%, could produce elastic modulus and flexural strength above 13,300 MPa and 2.1 MPa at the age of 28-days. On a 2% - 8% slope, its horizontal permeability was valued + 3.5 higher than the minimum requirement. From 100% of the total pore, there was 71% inter-connected pore. The mechanical properties test result showed that pervious concrete could be recommended to replace lean concrete and class A aggregate as rigid pavement base layer and drainage layer. However, the potency of clogging on pervious concrete layer still must be considered. Flexural-fatigue behavior that represented by stress ratio, number of fatigue repetition, flexural strain, flexural stiffness, and cracking progress showed that the 2-layer beam with the bonded condition had a better fatigue resistance than 1-layer beam and 2-layer beam with the unbonded condition. Based on the ultimate shear stress approach, the interface condition of the 2-layer beam with the bonded condition was located on the intermediate case condition (0,1 MPa < ? < 10 MPa). The dissipated energy could also be used as an indicator of the fatigue response of the 2-layer beam with the bonded condition. In the development of 2-layer system flexural-fatigue model, the unbonded condition fatigue life was influenced by stress ratio and 1-dimension heterogeneity level, whereas the bonded condition fatigue life was influenced by stress ratio and void content. The pervious concrete flexural-fatigue model of the 2-layer system with the bonded condition could be utilized to predict the fatigue life of a rigid pavement model that uses cement concrete as a surface layer and pervious concrete as a base layer by flexural strength ratio 2.1. However, the maximum stress ratio limit was needed in order to produce a minimum fatigue repetition for a highway. Based on the mechanistic model simulation, the bond strength of the interface layer had a crucial effect against the fatigue life of the 2-layer system rigid pavement.