2. Optimum Use of Material - Dirk Heyer

8/3/2019 2. Optimum Use of Material - Dirk Heyer

1/28

Technische Universitt Mnchen

1

Optimum Use of Materials

Dr.-Ing. Dirk Heyer

Zentrum Geotechnik, TU Mnchen

2nd International Seminar

Earthworks in Europe3rd & 4th June 2009 Royal Geographical Society, London


2/28


2

Motivation / reasons for optimum use of materials

General aims of the German laws about waste

Saving of non-renewable resources

Minimizing of (mineral) waste (3 steps):

1. Avoiding

2. Utilization/Recycling

3. Disposal


3/28


3

Motivation for optimum use of materials

Practical experience using material in earthworks

Preference in using high quality soils in earthworks (e.g. gravel) Usage of secondary raw material (e.g. recycled building material)

and excavated soils on site with suboptimalsoil-mechanical characteristics(e.g. organic soil, weak rock)

is not common


4/28


4

Objectives of optimum use of materials

Material Efficiency

Optimum use of naturalbuilding material in earthwork

Usage of nearly all on siteavailable soils

Usage of secondary rawmaterials

Avoid dumping

Optimize constructionmethods

Saving Resources

Reservation of pits/quarries forhigh quality materials

Minimize the demand on land

Minimize and optimizetransport routs

Optimize the durability ofearthworks

&


5/28


5

Objectives of optimum use of materials

Material Efficiency Saving Resources&

planning, design and construction

Realisation

main focus:

combining civil engineering and environmental interests

Requirement


6/28


6

Optimum use of materials main focus for a sustainable

use of materials

Establishing requirements of usage

Creating or modifying legal regulations Implementation in standards for road constructions

No difference between natural (primary) material and secondaryraw materials

Including in invitations of tenders and in building contracts

Verifying the feasibility

Verifying civil engineering and environmental feasibility

Creating model projects

Scientific monitoring of model projects

Material flow management must be established


7/28


7

Innovations in German environmental regulationsso called Ersatzbaustoffverordnung (blueprint Nov 07)

Objectives

Usage of mineral / demolition waste (secondary raw materials)

without negative effects for the environment Usage of recycling materials and industrial by-products

Protection of soil and ground-water

Field of Application Usage of unstabilized or stabilized materials in earth constructions

Materials that are concerned:

Soils from construction activities, preparation or interim storage Mineral waste from building activities

Recycling materials

Industrial by-products


8/28


8

Innovations in German (highway) construction regulations

M TS E Guidelines for Technical Safeguards in Earthworks

Technical safeguards

Structural and design measures

Protection of soil, ground-water and surface water

Construction methods

Proposed 6 main construction methods for

protective barriers, e.g. noise

embankments Possible transfer to other earthworks with similar boundaries


9/28


9

M TS E Guideline to Technical Safeguards in Earthworks

e.g. construction method A, sealing element sensitive to weatheringwithout drainage



10/28


10


M TS E Guideline to Technical Safeguards in Earthworks

e.g. construction method D, filling material to the core of the dam


11/28


11

ZTV E-StB 09 German Construction Rules for Earthworks

Revised version in 2009 including following objectives

Reuse of almost all soils

Explicit definitions for different kinds of mineral building materials forearthwork constructions

Technical terms of delivery for soils and building materials(TL BuB E-StB)

Geotechnical requirements for recycled aggregates

Including recycling materials and industrial by-products Adjustment to environmental rules (e.g. Ersatzbaustoffverordnung)



12/28


12

TL BuB E-StB 09 - Technical Terms of Delivery for Soils and other

Building Materials

Valid for the delivery of soils and building materials in earthworks regardingZTV E-StB

Requirements for soils and building materials regarding the ingredients, thegeotechnical properties and the environmental characteristics

Quality monitoring of soils and building materials must be carried out quality management system



13/28


13

TL BuB E-StB 09

Definition of soils and recycling materials

Industrial by-products

Metal slag

Slag from waste incineration

Slag from coal fired power plants

Slag and combustion residue from foundries

Residues of mining

10 Vol.-% 50 M.-%

recycling materialsoil containing mineral impuritiessoil

percentage of mineral impurities



14/28


14

Application Field: Mass Balancing

Surplus of soils disposal or for sale

following the requirements of Ersatzbaustoffverordnung

Shortage of soils delivery / purchase necessary

following the requirements of TL BuB E-StB

Transfer material from one site to another without changing theowner

German rules are yet undetermined



15/28


Requirements for compaction rates DPr (ZTV E-StB 09)

Area Types of soil DPr in % na in %

1 From formation level to 1,0 mdepth in embankments

and 0,5 m depthin cuts

GW, GI, GESW, SI, SE (coarse grained)

GU, GT, SU, ST (mixedgrained until 15 % fines)

100 -

2 1,0 m under formation level to thebottom of embankments

GW, GI, GESW, SI, SE (coarse grained)

GU, GT, SU, ST (mixedgrained until 15 % fines)

98 -

3 From formation level to the bottom ofembankments and und 0,5 m depth

in cuts

GU*,GT*, SU*, ST* (mixedgrained over 15 % fines)

U, T, OU, OT (fine grained)97

128 (6)**

** air pore content for water sensitve soils and non-durable rock


16/28


16

Soil improvement with lime or other additives

Often used, since the water content is to high for compaction,especially for soft/firm clays/silts with low plasticity

Soil stabilization with cement

Long term stability, also against frost, and high bearing capacity,

especially for uniform sands

Optimum Use of Materials Examples (1)Common processes


17/28


17

Usage of non-durable rocks in earthworks

Complex of problems

Loss of strength even aftercompaction possible

Specific requirements forcompaction technique necessary

Avoid loss of stability ordeformation

Ensure the durability of earthworks Only few instructions and

guidelines how to use thesematerials in German constructionregulations available

Optimum Use of Materials Examples (2)


18/28


18


Slake Durability Test to detect and to quantify non-durable rocks

testing equipment



19/28


19


Slake Durability Tests now included in German constructionregulations

Revised version of ZTV E-StB advises tightened compactionrequirements

Usage of non-durable rocks in earthworks is possible:

If material is examined in special investigations

If the material properties are concerned during planning,design and construction progress



20/28


20

Qualification of

Soils with mineral impurities, Recycling materials and

Industrial by-products in earthworks

Complex of problems

Often poor acceptance of thesematerials by the client

Inexplicit or unidentified soilmechanical properties

Compaction requirementstransferable to these products?

How to evaluate frost resistance?

How to evaluate the weathering

resistance of these materials?

slag from wasteincineration

crashedgas concrete

scoria



21/28


21

Soils with mineral impurities, recycling materials and

industrial by-products in earthworks

Results of the latest research

Evaluation of the weathering resistance of mineral impurities, recycling

material and industrial by-products Idea of analogous: non-durable rocks

Slake Durability Test

Soil mechanical investigations

Compaction properties

Bearing capacity

Shear strength

Evaluation of frost resistance



22/28


22




Due to their granular structure a classification comparable to soils is

possible and reasonable

To estimate the soil mechanical properties, it is necessary to know thecomposition of material in detail

Research methods usual for soils are qualified in principle to class theweathering resistance of these materials

Slake Durability Test combined with an extended evaluation



23/28


23




Usage in earthworks only after previous treatment (e.g. breaking,

grading, sieving) no usage of untreated demolition waste

Compaction properties of soils with mineral impurities and of recyclingmaterial generally clearly comparable to soils

German compaction requirements for earthworks can be adopted



24/28


24

Disaggregation and processing of cohesive

tunnel excavation materials

Complex of problems

- Disaggregation of cohesive soil (e.g. tertiary clay) during hydraulic

transportation from tunnel face to separation plant

- Generally high technical and economical effort for separation andreuse of the excavated cohesive soil

- Predicting the grain-size-distribution and disaggregation isnecessary to estimate the qualification for reusing in earthworks



25/28


25


tunnel excavation materialsResults of the latest research

- Laboratory test to describe the disaggregationduring hydraulic transport

- Small scale test to analyse the fundamental dependencies

- Pilot plant scale test to simulate hydraulic transportation

- Variation of transportation medium

- Water

- Bentonite suspension- Polymer suspension

- Analysing the estimated grain-size-distributionagainst the transport time, speed and distance

1,6m



26/28


26


tunnel excavation materialsResults of the latest research- Disaggregation of tertiary clay in water during hydraulic transportation depends on

- Plasticity

- Consistency- Calcium carbonate content

- Less disaggregation in water during hydraulic transport is only possible,if plasticity is > 20 %

- High calcium carbonate content can reduce disaggregation

- Using bentonite suspension nearly halve the disaggregation compared to water

- Suspension conditioned by polymers can prevent disaggregation



27/28


27

Munich Airport

Use of organic soils in earth constructions

Complex of problems

Large amount of organic topsoil

Dumping should be avoidedObjectives: Use in earthworks of

less importance

Noise barrier embankments

Visual protectionembankments

Hills for visitors

Testing of the geotechnicalapplicability by a model project



28/28


28

Munich Airport

Use of organic soils in earth constructions

Model project organic soil

Improvement of compaction technologies

Recording the suitability and feasibility of the planned construction byfield tests

Extension of the state of knowledge to the mechanical and hydraulicproperties of organic soils

Recording the soil mechanical properties of organic soils in field tests Conservation of evidence by long term monitoring


2. Optimum Use of Material - Dirk Heyer

Documents