Validation of a dynamic modulus predictive equation on the basis of spanish asphalt concrete mixtures

Abstract

Dynamic modulus is defined as the ratio of peak cyclic stress to peak cyclic strain under harmonic loading. It is one of the most important properties of asphalt mixtures, since it determines the strain response characteristics as a function of loading rate and temperature. Different simplified models exist that can predict this variable from mixture composition and binder rheological data, with Witczak and Hirsh models being the most widely accepted. These models have been evaluated in the present study, on the basis of 352 data points from eight asphalt concrete mixtures that were tested between −5 and 60 °C. A new model is also formulated which improves predictions of the previous ones for Spanish mixtures, even though it is a relatively simple equation that requires very limited binder rheological data compared to Witczak and Hirsch models. RESUMEN: Validación de una fórmula predictiva del módulo dinámico a partir de mezclas españolas tipo hormigón bituminoso.El módulo dinámico es la relación entre los picos de tensión y deformación bajo carga armó-nica. Es una de las propiedades más importantes de las mezclas bituminosas, ya que determina la respuesta deformacional en función de la velocidad de carga y la temperatura. Existen diferentes modelos simplificados que permiten predecir esta variable a partir de la composición de la mezcla y de las características reológicas del betún, siendo los de Witczak y el de Hirsch los más ampliamente aceptados. Dichos modelos han sido evaluados en el presente estudio a partir de 352 puntos procedentes de ocho mezclas tipo hormigón bituminoso que fueron ensayadas entre −5 y 60 °C. Así mismo, se ha formulado un nuevo modelo que mejora las predicciones de los anteriores para las mezclas españolas, aun tratándose de una ecuación relativamente simple que requiere una mínima información reológica del betún en comparación con los modelos de Witczak y Hirsch.

Analysis of the sensitivity of the impact resonance frequency test as a tool to determine the elastic properties of bituminous materials

“…Models such as those developed by Witzack (7) or Hirsch (8), allow for the evaluation of this property based on parameters related to the materials (mineral skeleton, type of binder used, voids content, etc.). However, when evaluating pavement deterioration, this parameter is used rather less extensively during the service life when compared with the design phase.…”

Estimation of dynamic modulus of stiffness of conventional bituminous hot mix pavement layers and comparison with Marshall design method data

“…Pahalı ve zaman alıcı laboratuvar test gerekliliklerini hafifletmek için 1990'lı yıllardan itibaren , hacimsel hesaplamalara göre yapılan karışım numuneleri değerlendirilerek tahmin modelleri geliştirilmiştir. Günümüzde karışım tipi ve dizaynlarının değişmesi, alternatif malzeme ve geri dönüşüm kullanımı artmasından dolayı yeni tahmin modelleri ve geliştirilmiş modellerin kalibrasyon yapılarak yeni modeller geliştirilmeye çalışılmaktadır [10-11-12].AASHTO 2002 M-A Kaplama Tasarım Rehberinde ikinci ve üçüncü hiyerarşik seviyeler için |E*| tahmininde, Witczak ve Hirsch model denklemlerinin uygulanması kabul edilmiştir [13].…”

A statistical methodology for reliable evaluation of calibrated dynamic modulus regression models

“…Several authors proposed empirical models to predict |E * |, expressed as equations that relate characteristics of the component and mix design parameters to the stiffness properties of the mixtures, including WITCZAK and FONSECA [2], CHRISTENSEN JUNIOR et al [3], BARI and WITCZAK [4], MATEOS and SOARES [5], YANG and YOU [6], and SAKHAEIFAR et al [7].…”