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					CEMENTITIOUS STABILISATION
  OF ROAD CONSTRUCTION
   MATERIALS: QUO VADIS

         Phil Paige-Green,
     CSIR-Transportek, Pretoria

         Frank Netterberg
            Consultant
             INTRODUCTION

 Stabilisation of marginal materials is still an
  important part of road building in RSA
 Will probably become more important as good
  materials are depleted
 Specification of stabilisation is based on:
    – COLTO Standard Specs for R&B (1996)
    – with assistance from Draft TRH 13 (1986)
                INTRODUCTION
   Cement stabilisation experience incorporated in
    COLTO and TRH13 was based mainly on the use
    of:

    –   Ordinary Portland Cement (SABS 471)
    –   PBFC (SABS 626)
    –   Portland cement blends (SABS 831)
    –   Portland flyash cement (SABS 1466)


   Things have changed !!
          SABS ENV 197-1
 In 1992, became a European pre-standard (ENV)
 After 3 years should be upgraded to European
  standard (EN) ??
 Adopted “as is” by SABS in 1996 for RSA
 Applicable to “common cements”
 Similar spec for masonry cements (SABS ENV
  413-1)
 Concentrate on SABS ENV 197-1 as this is most
  relevant for roads
           NEW REQUIREMENTS
 Totally different classification system
 5 cement types
    – 9 groups (depend on additive)
          19 subgroups (depend on composition)


   Also classified by strength and rate of strength
    gain (6 additional permutations)
           CLASSIFICATION
 I Portland cement
 II Other Portland cements
      Portland slag cement
      Portland silica fume cement

      Portland flyash cement

      Portland limestone cement

      Portland composite cement

 III Blastfurnace cement
 IV Pozzolanic cement
 V Composite cement
         Strength requirements
                Compressive strength (MPa)
Strength     Early strength    Standard strength
  class    2 days      7 days       28 days
  32.5        -        ≥ 16.0  ≥ 32.5     ≤ 52.5
 32.5R     ≥ 10.0         -
  42.5     ≥ 10.0         -    ≥ 42.5     ≤ 62.5
 42,5R     ≥ 20.0         -
  52.5     ≥ 20.0         -    ≥ 52.5        -
 52.5R     ≥ 30.0         -
STANDARD DESIGNATION

   Cement ENV 197-1 CEM I 32.5
    – (equiv to OPC ?)


   Cement ENV 197-1 CEM II/A-S 42.5
      CHEMICAL PROPERTIES
SABS 471                       SABS ENV 197-1
Lime sat factor 0.66 -1.02     CaO/SiO2 ≥ 2
MgO cement ≤ 5%                MgO clinker ≤ 5%
Max SO3 = 3.0 – 3.5 %          Max SO3 = 3.5 – 4.0 %
                               (4.5)
Max LoI = 4 %                  Max LoI = 5 %
Max insoluble residue = 2.5%   Max insoluble residue = 5%
Chloride N/S                   Max chloride 0.1%
Pozzolanicity N/S              Pozzolanicity - Yes
    PHYSICAL PROPERTIES
        Property            SABS 471         ENV 197-1
Max % >212 μm             1.2               N/S
                          0.5 (RH)
Min specific surface area 2250              N/S
(cm2/g)                   3250 (RH)
Min UCS (MPa) 3 days 16          21 (RH)    Earlier table
                  7 days 24      28 (RH)
Min transverse str (MPa)
  3 days                  1.8    2.8 (RH)   N/S
  7 days                  2.8    3.8 (RH)   N/S
  PHYSICAL PROPERTIES (cont)


       Property             SABS 471    ENV 197-1
Setting times:
   Min initial (min)   45      45 (RH) 45 – 60
   Max final (hrs)     10      10 (RH) N/S
Soundness:             10      10 (RH) 10
 Max expansion (mm)
                               STRENGTH

                 60                                       Portland
                                                          cement
                 50                                       RH Portland
Strength (MPa)




                                                          cement
                 40                                       32.5
                 30                                       32.5R
                 20                                       42.5
                 10
                                                          42.5R
                 0
                                                          52.5
                      0   5   10   15      20   25   30
                                                          52.5R
                                        Days
                                                          Linear (52.5R)
         Strength requirements
                Compressive strength (MPa)
Strength     Early strength    Standard strength
  class    2 days      7 days       28 days
  32.5        -        ≥ 16.0  ≥ 32.5     ≤ 52.5
 32.5R     ≥ 10.0         -
  42.5     ≥ 10.0         -    ≥ 42.5     ≤ 62.5
 42,5R     ≥ 20.0         -
  52.5     ≥ 20.0         -    ≥ 52.5        -
 52.5R     ≥ 30.0         -
      CHEMICAL PROPERTIES
SABS 471                       SABS ENV 197-1
Lime sat factor 0.66 -1.02     CaO/SiO2 ≥ 2
MgO cement ≤ 5%                MgO clinker ≤ 5%
Max SO3 = 3.0 – 3.5 %          Max SO3 = 3.5 – 4.0 %
                               (4.5)
Max LoI = 4 %                  Max LoI = 5 %
Max insoluble residue = 2.5%   Max insoluble residue = 5%
Chloride N/S                   Max chloride 0.1%
Pozzolanicity N/S              Pozzolanicity - Yes
    PHYSICAL PROPERTIES
        Property            SABS 471         ENV 197-1
Max % >212 μm             1.2               N/S
                          0.5 (RH)
Min specific surface area 2250              N/S
(cm2/g)                   3250 (RH)
Min UCS (MPa) 3 days 16          21 (RH)    Earlier table
                  7 days 24      28 (RH)
Min transverse str (MPa)
  3 days                  1.8    2.8 (RH)   N/S
  7 days                  2.8    3.8 (RH)   N/S
  PHYSICAL PROPERTIES (cont)


       Property             SABS 471    ENV 197-1
Setting times:
   Min initial (min)   45      45 (RH) 45 – 60
   Max final (hrs)     10      10 (RH) N/S
Soundness:             10      10 (RH) 10
 Max expansion (mm)
                               STRENGTH

                 60                                       Portland
                                                          cement
                 50                                       RH Portland
Strength (MPa)




                                                          cement
                 40                                       32.5
                 30                                       32.5R
                 20                                       42.5
                 10
                                                          42.5R
                 0
                                                          52.5
                      0   5   10   15      20   25   30
                                                          52.5R
                                        Days
                                                          Linear (52.5R)

				
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posted:4/11/2011
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