africa re:load 14 Gluth - Inorganic Binder Systems for Innovative Panel Technology in East Africa

LightSHIP
Inorganic Binder Systems for Innovative Panel Technology in
East Africa
G. J. G. Gluth, W. Z. Taffese, G. S. Kumaran, H. C. Uzoegbo, H.-C. Kühne

Urban population
*projection
Urban population in Africa
World Urbanization Prospects: The 2007 Revision; United Nations: New York, 2008.

Need for affordable building materials
Large increase in urban population
e.g., population of Addis Ababa has doubled nearly every decade
Associated problem of enormous pressure on social and physical infrastructures (slums)
Alemayehu, E. Y. PhD Thesis, Norwegian University of Science and Technology, Trondheim, 2008.
Large need for affordable buidling materials to construct housings, public buildings etc.

Magnesia boards
Approach in Addis Ababa: production of partition boards from magnesium oxychloride cement

The LightSHIP project
Partners:
EiABC / Addis Ababa University
KIST Kigali Institute of Science and Technology
University of the Witwatersrand, Johannesburg
BAM Federal Institute for Materials Research and Testing
German-African Business Association
Consido AG
Addis Ababa
African partners
Kigali
Johannesburg
European partners
www.google.de/maps

Generation of a continuing scientific partnership in the sector of building materials research
Analysis of problems and possibilities of the participating African countries related to the design, application and testing of building materials
Evaluation of possible approaches to overcome these problems and ultimately to develop new building materials for East Africa
Preparatory tests on available building materials
Development and preparation of follow-up cooperation
Project objectives

Specifications for building materials
Pre-fabricated elements are to be prefered.
optimised fabrication process and minimization of risk of failures
Elements should be easily transportable and easy to assemble.
The materials should be produced with the highest possible fraction of local resources.
Existing know-how in the participating countries should be used.
Artificial stones and partition boards

Lightweight concrete: mix design
Superplasticizer:
PCE1.38 kg/m³
(0.44% of cement mass)
* Blend of CEM I 32.5 R and CEM I 52.5 R (50% each)
** Water which is absorbed by the lightweight aggregates in the first 10 minutes.

Lightweight concrete: results
Bulk density: 1.19 g/cm³
Compressive strength (28 d): 18.8 MPa
Flexural strength (28 d): 1.3 MPa
Drawback: relies on Portland cement

Magnesium oxychloride cement
Compressive strength (28 d): 7.4 MPa
with fibres (28 d): 8.7 MPa
Flexural strength (28 d): 2.3 MPa with fibres (28 d): 6.1 MPa
Water absorption: 9.4%
Drawback: poor water resistance

Lightweight partition boards
4 point bending test (DIN 53293:1982)
Total thickness of board: 101 mm
Thickness of panels: 3 mm
Max. bending moment: 1.5 kNm/m
Flexural strength of panel: 5.4 MPa

Binder systems
Portland cement
too expensive; mostly imported; high energy consumption and CO2 emission
Magnesium oxychloride cement
poor water resistance
Alternative: natural pozzolans (volcanic rock)
Abundant in East Africa because of the Great Rift Valley ( flood basalts)
Addis Ababa
Easily available (open-pit mining)
Kigali
Already used: pumice as filler or aggregate for concrete and mortar
Dar es Salaam
Linlongwe
Wood, J.; Guth, A. (Michigan Technological University) http://geology.com/articles/east-africa-rift.shtml

Lime-pozzolan binders
Starting materials: lime + pozzolan
Dissolution of silicate in alkaline solution
Precipitation of calcium silicate hydrates (and other hydrates)
SiO2 + xCa(OH)2 + yH2O -> xCaO∙SiO2∙(x+y)H2O [“C-S-H“]
Ortega E. A. et al. Cem. Concr. Res. 2000,30, 1641-1646.
Compressive strength: up to ~20 MPa
compacted: up to ~40 MPa
Flexural strength: ~3 MPa
need for fibre reinforcement (?)

Geopolymers
Starting material: aluminosilicate + alkaline activator
Dissolution of silicate and aluminate species in alkaline solution
Condensation and gelation of alkaline aluminosilicate gel
Reorganisation and crystallization (zeolites)
Lloyd, R. R. et al. J. Mater. Sci. 2009,44, 608-619.
Compressive strength: up to ~80 MPa
Flexural strength: up to ~8 MPa
Short setting and hardening times

Summary
Partition boards and artificial stones are appropriate construction elements for East African countries.
Conventional binders based on Portland cement are too expensive.
Alternative binder systems could be lime-pozzolan binders or geopolymers based on natural pozzolans.
Abundant in East Africa
Cheap
Already in use
Contribution to less energy consumption and CO2 release
Lime-pozzolan binders can be strong enough to produce artificial stones.
The production of partition boards from lime-pozzolan binders may require the use of fibre reinforcement.  Use of geopolymers?

Thank-you‘s
Thank you
for your kind attention!
Funding:

africa re:load 14 Gluth - Inorganic Binder Systems for Innovative Panel Technology in East Africa

by icebauhaus on Sep 11, 2011

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africa re:load 14 Gluth - Inorganic Binder Systems for Innovative Panel Technology in East Africa Presentation Transcript