CONCRETE ADMIXTURE

Building Construction
CONCRETE ADMIXTURE

Overview

Material which is added in small quantity during the mixing process to the concrete to change the characterstics of fresh and hardened concrete

Fresh Concrete

  • Water reduction
  • Workability retention
  • Air content
  • Stable mix
  • Cohesive mix
  • Smooth pumping
  • Finishing time

Hardened concrete

  • Improvement in compressive strength
  • Improvement in flexural strength
  • Improvement in density
  • Early strength development
  • Improvement in water tightness
  • Improved durability

How do admixtures work?

  • They impart negative charges on cement grains
  • Cement grains repel each other- Inter particle electrostatic repulsion
  • Large molecules of PC admixtures act as barrier between the cement particles – Steric hinderence
  • Dispersion of cement grains prevent formation of lumps
  • Workability is improved

SIKA WATERTIGHT CONCRETE - ONE SOLUTION TO SATISFY ALL CONDITIONS

Sika 101 H

  • Based on crystalline technology (self healing)
  • Non-soluble crystalline structure formation in the capillaries

Sika® ViscoCrete® / Sikaplast

  • Effective water reduction- production of high quality durable concrete
  • Ensured workability on construction site

Before water contact – Area of dry concrete

  • Capillary network is filled with lime and some humidity

Concrete exposed to water without coating

  • Water penetrates through the concrete and fills the capillary network

Waterproofing concrete with a crystallisation slurry

  • Reactive compounds penetrate into the concrete through the capillary pores. The reaction between humidity, available lime and the active chemicals from the slurry forms insoluble complexes

ROCK ANCHORING

  • Use of Sikagard 694 , moisture insenstive putty for rock anchoring

Why we need joints?

SIKA WATERTIGHT CONCRETE SYSTEM : SIKA WATERSTOPS SOLUTIONS – INTRODUCTION

Definition of Joint

A joint is defined as the place in a concrete structure where two concrete sections meet (weakness)

  • Construction Joints (non movement)
  • Movement Joints

TYPES OF JOINTS [WITH DIFFERENT STRESSES]

JOINT TREATMENT