Technical Guide - Treatment of soils with lime and/or hydrolic binders
Application to the construction of pavement base layers
This guide codifies the technique of soil treatment with hydraulicbinders, in some cases in combination with lime, for the constructionof pavement base layers. It supplements the “Guide techniqueTraitement des sols à la chaux et/ou aux liants hydrauliques -Terrassement et couche de forme” (GTS – Sétra/LCPC, 2000) and theapplicable standards.
This guide codifies the technique of soil treatment with hydraulicbinders, in some cases in combination with lime, for the constructionof pavement base layers. It supplements the “Guide techniqueTraitement des sols à la chaux et/ou aux liants hydrauliques -Terrassement et couche de forme” (GTS – Sétra/LCPC, 2000) and theapplicable standards. The first part of the document explains the types of soils involved andthe specifications for uniformity. It details the content of studies andhow they change in nature from geological surveys to laboratory tests. The second part describes the design of treated soil pavement baselayers. It states the traffic classes for which these materials may beused and explains, with regard to the design method, the parametersthat are specific to treated soils, in particular the mechanicalcharacteristics measured in a laboratory weighted on the basis of theconditions at the site and the state of the interface. It ends withexamples of design using fine treated soils. The third part explains how works and the monitoring of the materialsshould be performed, the ways the materials should be prepared at theconstruction site, defines the levels of quality on the basis of theequipment used (in-situ and in a plant), the conditions of transport andlaying, the surface protection to be applied on the basis of forecaststresses and the quality control procedures. This document ends with a series of annexes dealing with the soil datasheet and the specifications of soils used in pavement base layers,some economic factors and, finally, a summary of the survey that wascarried out on treated soil structures constructed in France.
Contents
1 - Introduction .................................................................................................................................7
2 - Studies ........................................................................................................................................ 10
2.1 - The types of soil covered by the guide ...............................................................................10
2.2 - The progressive nature of studies .......................................................................................11
2.3 - Characterization of the deposit ...........................................................................................12
2.3.1 -Minimum features of the geotechnical survey ................................................................12
2.3.2 -Evaluation of the uniformity of the deposit..................................................................... 12
2.3.3 -The mechanical strength criterion of the granular fraction .......................................... 14
2.4 - Mix design studies................................................................................................................. 15
2.4.1 -Objectives of the mix design study ................................................................................... 15
2.4.2 -Need for pretreatment with lime ...................................................................................... 15
2.4.3 -Choice of binder for the mix design study ....................................................................... 15
2.4.4 -Soil specimen used for the study ...................................................................................... 15
2.4.5 -Complete study .................................................................................................................... 16
2.4.6 -Limited study ........................................................................................................................ 17
2.4.7 -Identification of the constituents........................................................................................ 17
2.4.8 -Reference tests for compaction .......................................................................................... 17
2.4.9 -Study of the immediate stability .......................................................................................... 17
2.4.10 -Specimens ............................................................................................................................. 18
2.4.11 -Conservation.......................................................................................................................... 20
2.4.12 -Performance .......................................................................................................................... 21
2.4.13 -Sensitivity study of mechanical performance......................................................................21
3 - Design ............................................................................................................................................. 22
3.1 - Traffic data................................................................................................................................... 23
3.1.1 -The Ti traffic classes.................................................................................................................. 23
3.1.2 -The TCi cumulative traffic classes............................................................................................ 23
3.1.3 -Aggressiveness of traffic ........................................................................................................... 24
3.2 - Classes of subgrade ..................................................................................................................... 25
3.3 - Design parameters........................................................................................................................ 25
3.3.1 -Materials........................................................................................................................................ 25
3.3.2 -The interface conditions.............................................................................................................. 29
3.4 - Pavement design ........................................................................................................................... 29
3.4.1 -Application .................................................................................................................................... 29
3.4.2 -Minimum qualities .......................................................................................................................29
3.4.3 -Types of structures........................................................................................................................ 30
3.4.4 -Surfacing layers ............................................................................................................................ 30
3.4.5 -Constructional measures ............................................................................................................ 30
3.5 - Verification of frost design ........................................................................................................... 31
3.6 - Examples of design ....................................................................................................................... 31
3.6.1 -First example (Table 26) ............................................................................................................ 31
3.6.2 -Second example (Table 27)....................................................................................................... 35
4 - Implementation .............................................................................................................................38
4.1 - Foreword .................................................................................................................................... 38
4.2 - Preparation of materials .......................................................................................................... 39
4.2.1 -Sorting of the material ........................................................................................................... 39
4.2.2 -Removing aggregate above a certain size ............................................................................39
4.2.3 -Pretreatment with lime .......................................................................................................... 39
4.2.4 -Creation of stockpiles and rehandling..................................................................................40
4.2.5 -Moistening .............................................................................................................................. 40
4.2.6 -Validity of the selected methods.......................................................................................... 42
4.3 - Manufacture ............................................................................................................................ 42
4.3.1 -The level of quality of the treatment equipment for pavement base layers ................ 43
4.3.2 -Treatment in situ .................................................................................................................. 47
4.3.3 -Treatment in a plant ............................................................................................................ 48
4.4 - Transport and laying.............................................................................................................. 49
4.4.1 -Transport of mixtures .......................................................................................................... 49
4.4.2 -Laying ....................................................................................................................................49
4.5 - Surface protection ..............................................Erreur ! Signet non défini.
4.6 - Surface protection ................................................................................................................. 51
4.6.1 -Characteristics related to the nature of the treated soils................................................. 51
4.6.2 -Mechanical stresses ............................................................................................................. 51
4.6.3 -Climatic stresses .................................................................................................................. 51
4.6.4 -The different types of surface protection ........................................................................ 52
4.6.5 -Choice of the type of surface protection ......................................................................... 53
4.7 - Quality control ...................................................................................................................... 56
5 - Abbreviations - symbols - definitions ................................................................................... 65
6 - Bibliography ............................................................................................................................. 68
7 - Annexes.................................................................................................................................... 75
7.1 - Annex A ................................................................................................................................ 75
7.2 - Annex B ................................................................................................................................ 76
Specifications for soils used in pavement base layers............................................................. 76
Economic factors.......................................................................................................................... 77
7.3 - Annex C ................................................................................................................................ 78
The contribution of each item to the cost of the treated soil in question..............................78
The contribution of each piece of machinery to the cost of the treated soil in question ... 78
7.4 - Annex D ................................................................................................................................ 79
