TY - CONF A1 - Schmidt, Wolfram A1 - Radlinska, A. A1 - Nmai, C. A1 - Buregyeya, A. A1 - Lai, W.L. A1 - Kou, S. ED - Uzoegbo, H.C. ED - Schmidt, Wolfram T1 - Why does Africa need African concrete? An observation of concrete in Europe, America, and Asia - and conclusions for Africa T2 - ACCTA - International conference on advances in cement and concrete technology in Africa 2013 (Proceedings) N2 - Portland cement, as we know it today, has its origin in Great Britain approximately 170 years ago. Since then, concrete technology has spread out to Europe, the United States, and Japan, where it became a key component for rapid industrial development. Europe, the Unites States and many Asian countries today have developed a high level of technology regarding concrete construction. However, each of them has a unique history and as a result, different “concrete philosophy” depending upon the social, environmental and financial boundary conditions, as well as their evolution throughout the years and local construction traditions. As a result, the word concrete may refer to rather different materials in America, Europe, and Asia. Apart from South Africa, most sub-Saharan African countries cannot look back on a similarly long cement and concrete history. Cement and concrete are rather new materials and not yet well established. This gives African engineers the unique opportunity to learn from past mistakes and to develop a concrete technology, which refers to the best available practice. However, in many sub-Saharan African countries, standards and regulations are adopted (preferably from Europe or the US) without consideration of the historical background of these standards. Although this practice helps saving resources for the implementation, it does not necessarily yield the best result in the African environment, and also from an economic point of view it might come back disadvantageously due to unnecessary overdesigning. By comparing the differing states-of-the-art in North America, Europe, and Asia, this paper emphasizes, how regional conditions determine the practice of concrete technology in the sub-Saharan area. It is therefore important for Africa to develop a unique African concrete technology, which is perfectly fitted to the specific local conditions, even if it may vary distinctively from the established practice elsewhere. The paper concludes that African nations should effort into adapting existing principles that have proved to function well rather than adopting existing standards. T2 - ACCTA - International conference on advances in cement and concrete technology in Africa 2013 CY - Johannesburg, South Africa DA - 28.01.2013 KW - Cement KW - Casting environment KW - Concrete KW - Durability KW - Standards PY - 2013 SN - 978-3-9815360-3-4 SP - 1139 EP - 1147 AN - OPUS4-27767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akindahunsi, A. A. A1 - Schmidt, Wolfram A1 - Uzoegbo, H.C. A1 - Iyuke, S.E. ED - Uzoegbo, H.C. ED - Schmidt, Wolfram T1 - The influence of starches on some properties of concrete T2 - ACCTA - International conference on advances in cement and concrete technology in Africa 2013 (Proceedings) N2 - Starches and its derivatives are known to exhibit viscosity modifying characteristics. In an ongoing work, the influence of com and cassava starches on some properties of concrete such as compressive strength, heat of hydration and creep are examined. Various percentages (0.0, 0.5, 1.0, 1.5 and 2 %) of starches by weight of cement were added to concrete mixes prepared in the laboratory. Preliminary results of compressive strengths showed that both starches have some positive impact (e.g. there was 5.3 % increase in strength due to a 1 % addition of com starch by weight of cement in comparison to the control while cassava starch of the same percentage gave 4.9 % increase in strength) at certain percentages of starch addition to concrete at 28 days. The creep and hydration results shows the starch additions compares well and in some instance performs better. T2 - ACCTA - International conference on advances in cement and concrete technology in Africa 2013 CY - Johannesburg, South Africa DA - 28.01.2013 KW - Starches KW - Concrete KW - Compressive strength KW - Heat of hydration KW - Creep PY - 2013 SN - 978-3-9815360-3-4 SP - 637 EP - 645 AN - OPUS4-27756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -