Introduction

Basic Relationship

Chemical Admixtures

Background Data

Design Parameters

Design Procedure

INTRODUCTION

ACI 211.1-91, Reapproved 2009, states: "Concrete is composed principally of aggregates, Portland cement, and water, and many contain other cementitious materials and/or chemical admixtures. It will contain some amount of entrapped air and may also contain purposely entrained air obtained by use of admixture or air-entraining cement. Chemical admixtures are frequently used to accelerate, retard, improve workability, reduce mixing water requirements, increase strength, or alter other properties of the concrete. The selection of concrete proportions involves a balance between economy and requirements of placeability, strength, durability, density, and appearance."