TY - CONF A1 - Schmidt, Wolfram T1 - Challenges of the African environmental conditions for concrete mixture composition N2 - Concrete technology was exposed to a rapid development during the last three decades. For the longest time in its history, concrete was considered as a three component System consisting of aggregates, which are bound by the hardened cement paste consisting of hydrated cement. Traditionally, the only way of adjusting the consistency of concrete was using well adjusted aggregates and grading curves and adding excess water to the concrete, accepting that the latter in return reduces strength and durability. During the last three decades, however, concrete has developed further from a three component System towards an (at least) five component system, since the use of mineral additions and Chemical admixtures has become state of the art. Both components are able to enhance the workability, the compactability, and the density of the microstructure with effects on strength, ductility and durability, while cement can be saved in parallel. Due to reasonable use of admixtures and additions, concrete can be designed to match mechanically high performance specifications. Traditionally, cement paste was considered the weakest component in concrete. Flowever, in modern concrete a good paste composition can yield highest performance, passing the role of the mechanical bottleneck towards the aggregates. T2 - Workshop cement and concrete for Africa CY - Berlin, Germany DA - 17.08.2011 KW - Cement KW - Concrete KW - Mixture composition KW - Africa KW - Climatic conditions PY - 2011 SN - 978-3-9814281-4-8 SP - 37 EP - 49 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-24780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Gluth, Gregor T1 - Knowledge transfer and quality assurance - key factors for the future prospects of building with cement in Africa / Wissentransfer und Qualitätssicherung - Schlüsselfaktoren für die Zukunftsperspektiven der Bauweise mit Zement in Afrika KW - Africa KW - Cement KW - Concrete KW - Proficiency testing KW - Round robin PY - 2012 SN - 0949-0205 N1 - Sprachen: Deutsch/Englisch - Languages: German/English VL - 65 IS - 9 SP - 34 EP - 38 PB - Bauverl. BV CY - Gütersloh AN - OPUS4-26535 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Priebe, Nsesheye Susan A1 - Schmidt, Wolfram A1 - Gluth, Gregor A1 - Florea, M.V.A. A1 - Kumaran, G.S. A1 - Akindahunsi, A. A. A1 - Uzoegbo, H.C. A1 - Oslakovic, I.S. ED - Alexander, M. G. ED - Beushausen, H.-D. ED - Dehn, F. ED - Moyo, P. T1 - Concrete knowledge improvement in sub-Saharan Africa T2 - 3rd International conference on concrete repair, rehabilitation and retrofitting III CY - Cape Town, South Africa DA - 2012-09-03 KW - Education KW - Research sub-Sahara KW - Africa KW - Cement KW - Concrete PY - 2012 SN - 978-0-415-89952-9 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. IS - Theme 5 SP - 1459 EP - 1465 PB - CRC Press CY - London, UK AN - OPUS4-26508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Uzoegbo, H.C. A1 - Bjegovic, D. A1 - Schmidt, Wolfram A1 - Kitobo, W. T1 - SCM potential in Africa KW - Africa KW - Cement KW - Supplementary cementitious materials PY - 2012 SN - 0263-6050 SN - 0308-8855 IS - August SP - 27 EP - 38 PB - Swan CY - Leatherhead AN - OPUS4-27176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Kumaran, G.S. T1 - Clearing the way KW - Cement KW - Concrete KW - Africa KW - Research policy PY - 2012 SN - 0959-6038 IS - October SP - 86 EP - 88 PB - Holbrook & Son CY - Dorking AN - OPUS4-27177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Hirya, N.N.M. A1 - Bjegovic, D. A1 - Uzoegbo, H.C. A1 - Kumaran, S.G. T1 - Cement technology in sub-Saharan Africa-practical and scientific experiences N2 - Sub-Saharan Africa is populated by more than half a billion people, and rapid urbanization is creating challenges in the areas of housing, roads, railways, power supply, dams and water pipelines — aspects of infrastructure that are critical to the well being of the population. This situation indicates that cement and concrete will play a major role in the future construction technology in Africa, despite the fact that it does not have a long-lasting tradition over most of the continent. Although the continent is rich in natural resources for the production of mineral binder systems, many sub-Saharan African countries exhibit challenging boundary conditions, that have to be well understood in order to use cement and concrete technologies in a sustainable and reasonable way. KW - Africa KW - Cement KW - Technology transfer KW - SPIN PY - 2012 SN - 0002-7812 VL - 91 IS - 5 SP - 52 EP - 56 PB - American Ceramic Society CY - Westerville, Ohio AN - OPUS4-26075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram T1 - Start of round-robin test for cement testing in Africa / Start für Ringversuch zur Zementprüfung in Afrika KW - Africa KW - Cement KW - Concrete KW - Proficiency testing KW - Round robin PY - 2012 UR - http://www.bft-international.com/de/artikel/bft_2012-08_Start_fuer_Ringversuch_zur_Zementpruefung_in_Afrika_1468912.html SN - 0373-4331 SN - 1865-6528 N1 - Sprachen: Deutsch/Englisch - Languages: German/English VL - 08 SP - 54 EP - 55 PB - Bauverl. CY - Gütersloh AN - OPUS4-26429 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Priebe, Nsesheye Susan A1 - Kühne, Hans-Carsten T1 - Optimising the rheology of concrete for sub-Saharan African boundary conditions / Optimierung der Rheologie von Beton für Rahmenbedingungen in Subsahara-Afrika N2 - Die Zement- und Betontechnologie in Afrika hat keine ähnlich lange Tradition wie viele Länder der nördlichen Hemisphäre. In vielen afrikanischen Ländern ist die Bauindustrie jedoch von Wachstum gekennzeichnet und hier werden Zement und Beton zukünftig zweifelsohne an Bedeutung gewinnen. KW - Africa KW - Cement KW - Concrete KW - Proficiency testing KW - Round robin PY - 2012 SN - 0373-4331 SN - 1865-6528 N1 - Sprachen: Deutsch/Englisch - Languages: German/English N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. VL - 78 IS - 09 SP - 60 EP - 67 PB - Bauverl. CY - Gütersloh AN - OPUS4-27338 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marinescu, M.V.A. A1 - Schmidt, Wolfram A1 - Priebe, Nsesheye Susan A1 - Uzoegbo, H.C. A1 - Stipanovic Oslakovic, I. A1 - Kumaran, G.S. A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Rogge, Andreas T1 - Recent developments and perspectives regarding the standardisation and quality surveillance of cement in the east, central and south african region N2 - The cement and concrete market in East, Central and Southern Africa is highly fragmented. The concrete industry in this area consists of multiple parties, including producers and suppliers of construction materials, formal and informal contractors, engineers and architects, unions of trades persons and workmen, governmental bodies and formal institutions of research and education. All these institutions mostly do not interact adequately, which makes building with cementitious materials susceptible to damage and failures. Completely opposed to the situation in Europe or North America, cement in Africa is often unaffordable, while manpower is cheap, which results in a questionable economisation of cement. Typically, there is not sufficient awareness of methods to sensibly reducing the cement content in concrete or replace Ordinary Portland Cement by adequate alternative materials. Research activities in this field of technology are often missing completely. Only few countries in the area, such as South Africa, are exempted from these issues. This paper presents the SPIN project, which is a joint project of a consortium of 8 African and 3 European partners within the ACP Science and Technology Programme. The project is funded by the EC and ACP Secretariat is the project body. The main objective of the current project is to strengthen the cement and concrete industry in the East and Central African regions. The project shall generate reasonable solution strategies to implement clean, safe and sustainable cement and concrete technology on the African continent, including general and specific guidelines for sensible application. Furthermore it shall be the kick-off for future projects, research activities and the world-wide expansion of a European-African network. The paper addresses special problems the cement and concrete market in Eastern, Central and Southern African countries has to face. Several options are presented in detail, which shall help overcoming the current situation. Customized solutions for the African market include rational methods for reducing the amount of cement used and the replacement of Ordinary Portland Cement with cheaper alternatives. The use of recycled concrete through a new and economically effective method, as well as the opportunity of using locally available resources is also discussed. T2 - 13th International congress on the chemistry of cement CY - Madrid, Spain DA - 03.07.2011 KW - Africa KW - Clean and safe cement production KW - Scientific network PY - 2011 SN - 978-84-7292-400-0 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. SP - 1 EP - 6 AN - OPUS4-24041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Tchetgnia Ngassam, Ines A1 - Breitschaft, G. A1 - Virchow, S. ED - Diouri, A. ED - Boukhari, A. ED - Ait Brahim, L. ED - Bahi, L. ED - Khachani, N. ED - Saadi, M. ED - Aride, J. ED - Nounah, A. T1 - Challenges of the growing African cement market – environmental issues, regulative framework, and quality infrastructure requirements N2 - The African cement, concrete and construction business is growing at rapid pace. The cement sales are expected to grow rapidly until 2050. The number of newly built cement plants increases dramatically and in addition more cements are being imported from outside the continent, e.g. from Turkey, Pakistan, Indonesia, and China, driven by overcapacities in the countries of origin. This causes a high number of potentials and challenges at the same time. Newly built cement plants can operate directly at best technological state of the art and thus incorporate more sustainable technologies as well as produce new and more sustainable products such as cements blended with sustainable supplementary cementitious materials such as calcined clays, and industrial or agricultural by products. At the same time the new variety of binding agent as well as the international imports, which are driven by price considerations, make the cement market prone to quality scatter. This puts pressure on the quality control regulations and institutions to ensure safety of construction, healthy application, and environmental safety for the population. The paper presents possible solutions to build up the rapidly increasing African cement production more sustainably than in the rest of the world as well as the related challenges and obstacles that need to be overcome. Based on experiences with a series of pan-African cement testing laboratory proficiency schemes conclusions are made on technical, regulative and political level. T2 - 2nd International Congress on Materials & Structural Stability (CMSS-2017) CY - Rabat, Morocco DA - 22.11.2017 KW - Quality Infrastructure KW - Africa KW - Proficiency Testing KW - Cement KW - Admixtures PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-444330 SN - 2261-236X VL - 149 SP - 01014-1 EP - 01014-8 PB - EDP Sciences CY - Les Ulis AN - OPUS4-44433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barucker-Sturzenbecher, Meike A1 - Schmidt, Wolfram ED - Schmidt, Wolfram T1 - Learning from the future - How children of Mukuru fancy the city of tomorrow N2 - Sustainability means meeting the needs of today without compromising the needs of the next generations. How can we meet the needs of the next generations, if we do not even know what these needs are? If we do not listen to the next generation and learn from them? Do we even meet the needs of today for everyone on earth? T2 - ISEE Africa - Innovation, Science, Engineering, Education CY - Nairobi, Kenya DA - 30.01.2019 KW - Urban planning KW - Concrete KW - Mukuru KW - Africa KW - Sustainability PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-484832 UR - http://isee-africa.com/wp-content/uploads/2019/07/Innovation-Science-Engineering-Education_High-Quality.pdf SN - 978-3-9818564-2-2 SP - 194 EP - 197 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-48483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Radebe, N. ED - Schmidt, Wolfram T1 - Biased by analytical equipment N2 - Today, in scientific events often a certain separation between researchers from laboratories with highly sophisticated equipment and those from less privileged laboratories can be observed. It is not an uncommon situation that results presented at conferences are rubbished or ridiculed because the investigator only used low-end analytical methods. The assessment of the study is then biased based on the equipment, regardless of the actual quality of the study. T2 - ISEE Africa - Innovation, Science, Engineering, Education CY - Nairobi, Kenya DA - 30.01.2019 KW - Analytics KW - Africa KW - Bias KW - Science KW - Research PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-484877 UR - http://isee-africa.com/wp-content/uploads/2019/07/Innovation-Science-Engineering-Education_High-Quality.pdf SN - 978-3-9818564-2-2 SP - 203 EP - 204 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-48487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Tchetgnia Ngassam, Ines Leana A1 - Breitschaft, Gerhard A1 - Virchow, Stephen T1 - Challenges of the growing African cement market – Environmental issues, regulative framework and quality infrastructure requirements N2 - The African cement, concrete and construction business are growing at rapid pace. The cement sales are expected to grow tremendously until 2050. The number of newly built cement plants increases dramatically and in addition more cements are being imported from outside the continent, e.g. from Turkey, Pakistan, Indonesia, and China, driven by overcapacities in the countries of origin. This causes a high number of potentials and challenges at the same time. New cement plants can operate directly at best technological state of the art and thus incorporate more sustainable technologies as well as produce new and more sustainable products such as cements blended with sustainable supplementary cementitious materials such as calcined clays, and industrial or agricultural by products. At the same time the new variety of binding agent as well as the international imports, which are driven by price considerations, make the cement market prone to quality scatter. This puts pressure on the quality control regulations and institutions to ensure safety of construction, healthy application, and environmental safety for the population. The paper presents possible solutions to build up the rapidly increasing African cement production more sustainably than in the rest of the world as well as the related challenges and obstacles that need to be overcome. Based on experiences with a series of pan-African cement testing laboratory proficiency schemes conclusions are made on technical, regulative and political level. T2 - 2nd International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 21.11.2017 KW - Quality infrastructure KW - Round Robin KW - Proficiency testing KW - Cement KW - Africa PY - 2017 AN - OPUS4-43543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram T1 - Agricultureal Waste for High Performance Construction - Potentials for Innovation, Markets, and Sustainability N2 - The presentation provides an overview of potentials for high performance construction materials based on local agricultural waste materials in different regions in Africa. T2 - 5th German-African Infrastructure Forum 2017 CY - Düsseldorf, Germany DA - 08.11.2017 KW - Cement KW - Concrete KW - Bio-based materials KW - Sustainability KW - Africa PY - 2017 AN - OPUS4-43545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram ED - Banjad Pecur, Ivana ED - Baricevic, Ana ED - Stirmer, Nina ED - Bjegovic, Dubravka T1 - Potentials for sustainable cement and concrete technologies - Comparison between Africa and Europe N2 - The fundamental knowledge about cement and concrete has made enormous progress over the last decades, and today it would be possible to find optimised sustainable concrete solutions tailored for every given boundary framework and raw material supply. However, this knowledge barely finds implementation into practice despite the urgent global need to minimise carbon emissions and energy consumption. A major reason is that most concrete developments were historically made in the northern hemisphere, where today over-regulations and stagnating market perspectives slow down innovation drive towards higher sustainability. In most African countries, however, sustainable building is simply an urgent real-life problem. The demand for building is enormous, Standard solutions are not an option, and the pool of innovative local raw materials and concrete concepts is enormous. The paper provides a comprehensive comparison between the boundary frameworks of Europe and Africa, and it is explained why local African solutions shall be given priority over imported solutions. Examples of local African concrete solutions are given, and ideas for a rapid implementation are developed. Most of the potentially useful materials such as agricultural ashes, natural and calcined pozzolans, polysaccharides, etc. have not yet been subject to intensive research to date. Therefore, it is not unlikely to assume that with an open mind for non-Standard solutions, combined with creativity and particularly knowledge and awareness, the next generation of innovative and sustainable concretes will be developed and applied on the African continent. Therefore, the conclusion is that particularly the African continent provides the best starting position to develop better and more sustainable concrete solutions than anywhere else in the world. Hence, Africa can become a global pioneer in green cement and concrete technology with impact to the entire world. N2 - Posljednih desetljeća načinjen je golem napredak u temeljnim znanjima o cementu i betonu. Danas bi bilo moguće naći rješenja za optimalni održivi beton primjeren svakom danom okviru i dobavi sirovina. Međutim, takvo znanje jedva da se primjenjuje u praksi unatoč hitnoj globalnoj potrebi smanjenja na najmanju mjeru emisija ugljika i potrošnje energije. Glavni je razlog što je većina razvoja u području betona tijekom povijesti načinjena u sjevernoj hemisferi gdje danas preregulacija i perspektiva stagnirajućeg tržišta usporavaju inovacije ka većoj održivosti. Međutim, u većini afričkih zemalja održiva gradnja jednostavno je hitni problem svakodnevice. Zahtjevi za gradnjom su golemi, obična rješenja nisu opcija, rezerve inovativnih lokalnih sirovina i mogućnosti primjene betona su golemi. U radu se daje sveobuhvatna usporedba graničnih okosnica Europe i Afrike, a objašnjeno je zašto se lokalnim afričkim rješenjima mora dati prioritet pred uvezenim rješenjima. Većina potencijalno korisnih materijala kao što su pepeli iz poljoprivrede, prirodni i kalcinirani pucolani, polisaharidi itd. do danas nisu bili predmetom intenzivnih istraživanja. Stoga nije nevjerojatno pretpostaviti da će se Nova generacija inovativnih i održivih betona razviti i primijeniti na afričkom kontinentu uz otvorenost prema nestandardnim rješenjima i u kombinaciji s kreativnošću i posebno znanjem i sviješću. Stoga je zaključeno da naročito afrički kontinent osigurava najbolju početnu poziciju za razvoj boljih i održivijih betona nego bilo gdje u svijetu. Prema tome Afrika može postati svjetski pionir u tehnologiji zelenoga cementa i betona s utjecajem na cijeli svijet. T2 - 1st International Conference on Construction Materials for a Sustainable Future CY - Zadar, Croatia DA - 19.4.2017 KW - Africa KW - Sustainability KW - Cement KW - Concrete KW - Admixtures KW - Carbon emissions PY - 2017 SN - 978-953-8168-04-8 SP - 829 EP - 835 CY - Zagreb, Croatia AN - OPUS4-40977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Tchetgnia Ngassam, Inès A1 - Mbugua, Rose A1 - Adisa Olonade, Kolawole T1 - Promising bio-based rheology modifying agents for concrete N2 - Today, concrete engineers can vary consistencies between very stiff and self-compacting. The possibility to tailor rheological properties of concrete eventually opened up the path to multiple new technologies, where design criteria are no longer limited to the Young’s modulus and the compressive strength, but often comprise additional added value. It can therefore be concluded that the capability to control the rheology of concrete systems can be considered as the catalyst for concrete innovations such as polymer modified cementitious composites (PCC) self-compacting concrete (SCC), high-performance concrete (HPC), ultra-high performance concrete (UHPC) or strain hardening cement based composites (SHCC). In the same way rheology modifying admixtures will become key parameters in mastering the challenges of the next decades such as: - Additive manufacturing/3D-printing - Overcoming pumping height limitations - Casting at extreme temperatures - Tailored rheology at delivery In many regions in the Southern hemisphere, and particularly in Africa, the effective use of chemical admixtures for concrete could significantly contribute to solve problems induced by the challenging climatic conditions, but particularly in Africa it is difficult to use them, due to lacking local supply and supply infrastructure. For Africa, concrete admixtures are largely shipped or transported from Europe, the Arabian Peninsula, or Asia. The long distance transportation of chemicals is not very environmentally friendly and the economic consequences are dramatic: the agents are difficult to purchase, expensive, and there is not a large variety of products available in the market. However, bio-based chemicals have been used in construction for ages effectively. Due to the enormous relevance of rheology modifying admixtures it is worthwhile to recollect that nature provides an enormous variety of chemicals that can be used readily or with low processing. Today, the use of petrol based polycarboxylate ether superplasticizers has become quite common in concrete technology due to their versatility, but their uncomplicated and cost efficient availability is limited in most countries in Africa. However, alternatives are available, which can be found in many regions. Plant extracts have been used to modify the properties of concrete for long time. These plants are typically regionally abundantly available, cheap, and they are environmental friendly. They do not require special caring for seedlings, weeding or manuring to grow since they grow wildly. The talk will present an overview of various options for rheology modifying admixtures, that can be found in nature, and that may become a real alternative, once their interaction within the complex cementitious system is well understood. T2 - Rheologie komplexer Fluide: Theorie, Experiment und Anwendung, DRG/ProcessNet | Gemeinsame Diskussionstagung CY - Berlin, Germany DA - 13.3.2017 KW - Africa KW - Cement KW - Concrete KW - Admixtures KW - Polysaccharides KW - Cassava KW - Starch KW - Triumfetta Pendrata A. Rich KW - Nkui PY - 2016 AN - OPUS4-40979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -