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Moisture Related Problems in Stabilized Materials
Published in A. Gomes Correia, Fernando E.F. Branco, Bearing Capacity of Roads, Railways and Airfields, 2020
Particle size distribution analysis was performed as per ASTM D 422 on each aggregate material. The gradations are plotted in Figure 2. Results of particle size distribution analysis and Atterberg limits are subsequently used to classify the aggregate base materials.
Laboratory study and performance evaluation of cement treated base using chemical stabiliser
Published in Road Materials and Pavement Design, 2023
Supriya Marik, G. D. Ransinchung R. N., Aditya Singh, Lt. Prathmesh Khot
Cement-treated base is a common term which refers to a mixture of soils and/ or aggregates with measured amounts of cement and water. It stiffens and is hardened post proper compaction and curing to generate a strong, durable, frost resistant structure. Cement-treated aggregate base materials have advantages in enhancing the load-carrying capacity of pavement (Du, 2018). Xuan et al. (2012) reviewed the effect of mixture variables on the mechanical behaviour of CTB. The main properties that has been assessed were unconfined compressive strength (UCS), tensile strength and elastic modulus. It has revealed that the UCS is considered to be an important quality parameter of CTB. It was found out that variable factors controlling the UCS, such as quantity of cement, curing time, degree of compaction and so on, affect the structural behaviour of CTB also. UCS was the key parameter which influences the tensile strength and elastic modulus. They derived that the prediction models for mechanical characteristics of CTB can be established through mixture parameters.
Key performance indicators of aggregate base course waste management during the construction phase of a road project from the contractor’s perspective
Published in International Journal of Pavement Engineering, 2022
K. J. A. W. L. Jayasinghe, B. A. K. S. Perera, G. P. D. P. Senanayake
Material wastage can occur during any stage of construction (Teo and Loosemore 2001). Material waste is often generated during the construction stage of a project (Saidu and Shakantu 2017). Aggregate base course is a primary material used in road construction projects because the strength and performance of the roads depend on it (Kang et al. 2011). It is bulky and costly and has to be used in large quantities (Chowdhury et al. 2010, Tabassum 2016), and, therefore, has a high transportation cost. Thus, the investigation of aggregate base course wastage during the construction stage of a project is important (Wang et al. 2004, Choudhari and Tindwani 2017). Because of material wastage, contractors of road construction projects have to incur high costs (Ogbu and Adindu 2019). If contractors are not conversant with the designs and related documentation, errors and reworks could occur leading to material wastage (Dainty and Brooke 2004). Thus, the contractors of road construction projects have to be capable of on-site project management and design interpretation (Ajayi et al. 2017). To minimise the risks that a contractor of a road construction project has to face because of aggregate base course waste, effective waste management using appropriate strategies and Key Performance Indicators (KPIs) is necessary (Radujkovic et al. 2010).
Pervious concrete as an alternative pavement strategy: a state-of-the-art review
Published in International Journal of Pavement Engineering, 2020
Barnali Debnath, Partha Pratim Sarkar
Coarser aggregate beds are generally used as the base layer, which act as a bi-functional protecting course – the aggregate base layer plays a vital role in maintaining the structural integrity and controlling the load response spectra originating from traffic volume while also act as a storage reservoir basin for proper subgrade infiltration. For this purpose, the base thickness is generally kept higher than the conventional pavements so as to obtain a satisfactory reservoir volume. Suleiman et al. (2011) have used Falling weight deflectometer (FWD) for assessing the structural load response of the pervious concrete with the help of artificial neural networks (ANN) based back calculation method and have reported that the higher base thickness will reduce the overall pavement deflection. The Environmental Protection Agency of the United States (EPA 1999) has also recommended a pavement cross-section for higher base thickness. The American Concrete Association (ACI 522 2010) has recommended providing a subbase section below the base layer for providing vertical support and for acting as a storage basin.