The estimation of the elastic modulus of concrete is important in structural design. The characteristics of aggregate, especially its stiffness, have a profound influence on the elastic modulus of the concrete. However, this parameter is found not to be properly considered in the elastic modulus models used in current design codes, or in those developed by established organisations and individual researchers. In this study, the importance of stiffness and water absorption of natural aggregate and recycled and secondary aggregates are discussed. The parameters used in the existing elastic models are presented and three models, namely, ACI 209.2R-08, Eurocode 2 and B4, are assessed for their accuracy in estimating the elastic modulus of concrete made with both natural aggregate and recycled and secondary aggregates. A new empirical model essentially based on aggregate stiffness in the form of aggregate absorption, aggregate content and its ratio to cement content, has been developed for estimating the elastic modulus of concrete made with aggregate suitable for use in structural concrete.

中文翻译：

---

用天然、再生和二次骨料估算混凝土的弹性模量

混凝土弹性模量的估计在结构设计中很重要。骨料的特性，特别是其刚度，对混凝土的弹性模量有着深远的影响。然而，发现在当前设计规范中使用的弹性模量模型或由已建立的组织和个人研究人员开发的模型中没有正确考虑该参数。在这项研究中，讨论了天然骨料和再生骨料和二次骨料的刚度和吸水率的重要性。介绍了现有弹性模型中使用的参数，并评估了三个模型，即 ACI 209.2R-08、欧洲规范 2 和 B4，评估了它们在估计由天然骨料和再生骨料和二次骨料制成的混凝土的弹性模量方面的准确性。