Peerapong Jitsangiam

Mechanical behaviours of hydrated cement treated crushed rock base as a road base material in Western Australia

Hydrated cement treated crushed rock base (HCTCRB) is widely used as a base course material for Western Australian roads. In order to be able to use this material effectively, its shear strength, resilient modulus and permanent deformation characteristics should be investigated and clearly understood. This study aimed to carry out the results of implement laboratory testing, which was to assess the mechanical characteristics of HCTCRB. Our findings show that HCTCRB can be characterised as the cohesive granular material that has a cohesion (c) of 177 kPa and an internal friction angle (φ) of 42°. The resilient modulus characteristics can be modelled using the Uzan model. The permanent deformation characteristics can be modelled using the Sweere, G.T.H.s model. These models are based on the test results following the Austroads – APRG 00/33 test standard.

Experimental study of suction-monitored CBR test on sand-kaolin clay mixture

Conventional laboratory CBR test has been widely used for predicting bearing capacity of subgrade layer for pavement design. In unsaturated soil, suction is one of the key parameters for understanding the soil behavior. The analysis of CBR is commonly presented in CBR-water content relation. The information of CBR based on soil suction is very rare and more study is still required. This paper presents a laboratory experiment of CBR test with direct suction measurement. Suction-monitored CBR test is introduced by attaching tensiometers on CBR mold and its surcharge. The standard compacted test on various proportions of sand-kaolin clay mixtures starting from 0% (pure sand), 5%, 10%, and 20% of clay were used. The tests were performed with different value of water content in both soaked and unsoaked conditions. The results indicated that the CBR versus matric suction forms a bi-linear curve. The discussion is presented in term of CBR-water content and CBR-matric suction relation.

Performances of hydrated cement treated crushed rock base for Western Australian roads

Abstract: The resilient modulus (RM) of hydrated cement treated crushed rock base (HCTCRB) affected by amount of hydration periods, compaction and dryback processes was presented using repeated load triaxial tests. The related trends of RM corresponding to the different hydration periods still cannot be concluded. Instead, It is found that the moisture content plays more major influence on the RM performance. Higher additional water during compaction of HCTCRB, even at its optimum moisture content and induced higher dry density, led to the inferior RM performance compared to the sample without water addition. The RM of damper samples can be improved through dryback process and superior to that of the sample without water addition at the same moisture content. However, the samples without water addition during compaction deliver the comparable RM values even its dry density is lower than the other two types. These results indicate the significant influence of moisture content to the performances of HCTCRB with regardless of the dry density. Finally, the experimental results of HCTCRB and parent material are evaluated with the K - θ model and the model recommended by Austroads. These two models provide the excellent fit of the tested results with high degree of determination.

Fatigue Assessment of Cement-Treated Base for Roads: An Examination of Beam-Fatigue Tests

AbstractThis paper presents an examination of the fatigue characteristics of cement-treated base (CTB), a cement-stabilized material for use in road pavement construction based on CTB beam test specimens prepared and tested under laboratory conditions. The beam fatigue protocol for asphalt concrete, following the Austroads standard test method of AG:PT/T233, were adapted to examine the fatigue characteristics of the CTB test specimens. Standard road base (Granite/Diorite) from the local quarry in Western Australia was employed as the parent material of CTB. The beam-fatigue tests were conducted under the strain-controlled (constant strain) and stress-controlled (constant stress) testing conditions with varying cement contents (3–10%) of CTB test specimens. Two different loading waveforms of sinusoidal and haversine load curves were also investigated. The results show that for the strain-controlled testing condition, the fatigue characteristics of the CTB test specimens were not affected by the difference ...

Advanced Characteristics of Cement-Treated Materials with Respect to Strength Performance and Damage Evolution

AbstractCement-stabilized base (CSB), a cement-stabilized material for road pavement construction activities, generally has better essential properties than an unbound granular material, a commonly...

Dynamic Modulus Measurements of Bound Cement-Treated Base Materials

One of the most common methods used in road-pavement construction is the stabilizing of the conventional pavement base course layer. This is achieved by adding cement or lime to gain better material performance. However, obtaining modulus input parameters from a cement-stabilized base course layer for pavement-response analysis under real traffic conditions has proven difficult in that, to date, only ambiguous results have been produced. Using the flexural modulus or elastic modulus in the response analysis has certain limitations in embracing real pavement behavior under traffic and temperature conditions. Accordingly, a more reliable modulus input parameter for pavement analysis under traffic (cyclic) loads is required to obtain more precise and reliable outputs. Moreover, there is, at present, no test protocol to determine a suitable modulus for a cement-stabilized base material under the cyclic loading regime. This study aims to examine the real dynamic responses of cement-stabilized base course materials with a view to adapting the asphalt mixture performance tester (AMPT), a specifically designed dynamic modulus test machine used on asphalt concrete material. The AMPT dynamic modulus test has as an advantage in that loading and temperature regimes based on real pavement conditions can be rationally simulated and directly applied to the test samples. As such, the dynamic moduli of a cement-stabilized base course material can be obtained under different temperature and loading rates. Moreover, the effects of the dynamic strain range, cement content, and curing duration on the dynamic responses of a cement-stabilized base course material may also be examined. Cement-stabilized base course materials of 4 %, 5 %, and 6 % cement contents (by mass) were used as the study materials. The findings of this study indicate that curing durations and cement contents significantly influence the dynamic modulus values of cement-stabilized base course materials. However, the dynamic modulus is insignificantly affected by the changes in temperature and loading rates within a specific range of testing conditions in this study. The test results also reveal that cement-stabilized base course materials under examination behave in the manner of an elastic material when subjected to an axial compressive deformation of 45–105 μstrains. This is because of the dynamic modulus having no impact upon changes in the dynamic strain ranges or on the magnitudes of cyclic loads. Moreover, the dynamic moduli from this study were found to be much higher than the elastic moduli suggested by previous studies. However, the flexural moduli, which are derived from standard flexural tests, demonstrated close values to those of the dynamic moduli obtained in this study. In the study, the dynamic modulus of cement-stabilized base course materials, derived from the dynamic modulus using AMPT, could more reasonably embrace the dynamic responses of a material under traffic-loading conditions. This leads to a somewhat more reliable modulus input for the cement-stabilized base course materials used in a rational pavement design and analysis method.

Characteristics and Performance of Cement Modified–Base Course Material in Western Australia

AbstractHydrated cement–treated crushed rock base (HCTCRB) is produced by adding 2% Portland cement (by mass) to a standard crushed rock base (CRB) at an optimum moisture condition. The unique production process for HCTCRB is different from that of a common cement-treated base in that a remixing process is performed after the hydration of cement, preventing cementitious bonding to maintain the unbound material characteristics with an improvement in material engineering properties. This paper presents the resilient modulus (MR) and permanent deformation (PD) characteristics of HCTCRB after variable hydration periods, water addition during compaction, and dryback. The difference in material hydration periods affected the performance of HCTCRB. However, in this study, a consistent performance trend with various hydration periods could not be found. Moisture contents have a major influence on the properties of HCTCRB. The results indicate that a higher moisture content increases the PD and decreases the MR of...

Coarse bauxite residue for roadway construction materials

About 25 million tonnes of bauxite residue (BR) from alumina refining are generated in Australia each year. Managing this residue is costly, and the reuse of coarse BRs is becoming an increasingly attractive and sustainable solution to the problem. Using coarse BR in road construction has the potential for large volume reuse. This study investigated whether coarse BR is a viable road base material in Western Australia. A pozzolanic-stabilised mixture was created to improve the properties of the residue to satisfy the minimum requirements for road base. Laboratory tests for resilient modulus and permanent deformation were then carried out. Comparisons were made between the stabilised residue and conventional road base material used in Western Australia. The performance of the stabilised residue was superior to that of the conventional material, which can provide improved performance when used as road base material in Western Australia.

The Effects of Moisture Characteristics of Crushed Rock Base (CRB)

This paper reports the deformation behaviour of crushed rock with unsaturated condition under repeated cyclic loading triaxial (RLT) tests performed at different stress levels, in order to investigate the effect of moisture content to crushed rock performances and permanent deformation behaviour. Road surface rutting is the core basis of damage in flexible pavements which the mainly significant is crushed rock still unclearly thoughtful regarding deformation behaviour under real situation. RLT test is used to describe the various deformation responses of unbound granular materials (UGMs) by macro-mechanical observations. The main study focused on the influence of the moisture content. Moreover permanent deformation behaviour of crushed rock will be investigated and limit ranges of crushed rock should be considered in pavement analysis and design.

The use of fibre reinforced crushed rocks for the improvement of tensile strength

This study aims to report the possible use of fibre to improve the tensile strength of crushed rock base in a pavement in order to reduce the cracking of cemented material. As well is known, stabilized materials always present brittle responses under applied loads and suddenly collapse after peak loading. From this point, it means that cemented material only advances compressive behaviour and will never enhance long term performances such as fatigue and durability. Cemented crushed rock with fibre was selected to represent the tensile strength of pavement base material. Sophisticated tests were conducted to observe mechanical responses under applied loads such as indirect tensile and unconfined compressive strength, and the resilient modulus. The test results showed that fibre reinforcement improved the tensile strength and ductility of stabilized materials.