Unit for Construction Materials
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State-of-the-art test setup at UCMhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=2693State-of-the-art test setup at UCMRiaan Combrinck<p>​​​A state-of-the-art test setup for the direct tensile testing of plastic concrete was added to the already comprehensive list of testing equipment at the Unit for Construction Materials (UCM), in the Department of Civil Engineering. </p><p>The setup uses an air bearing to float an 80kg mould filled with fresh concrete without any friction. The air bearing and mould were machined using CNC technology to achieve the needed micrometer accuracy. The mould has a dog-bone shape to transfer the load from the mould to the fresh concrete sample.</p><p>The mould consists of two halves that are horizontally pulled apart via a servo-controlled linear mechanical actuator with a loading capacity of 1.7 kN. The setup is used to determine the tensile material properties of plastic concrete which adds significant value to the study of cracking in plastic concrete. <span style="line-height:1.6;">This in turn forms part of the current research conducted at the UCM regarding the behaviour of fresh and young concrete.  </span></p>
New Universal Testing Machine at UCMhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=2694New Universal Testing Machine at UCMRiaan Combrinck<p>​The Unit for Construction Materials (UCM), in the Department of Civil Engineering, welcomed a new universal testing machine as part of the testing equipment arsenal.  The machine is manufactured by Instron and has a 2 MN (around 200 ton) loading capacity in compression and tension. The crosshead of the machine is moved hydraulically for load application using pressurised oil. In addition to the supplied computerised control system, internal displacement transducer and load cell, various accessories such as clamps were also purchased to increase the versatility, as well as to simplify the load application of the machine. The machine is ideal for the testing of larger specimens such as concrete beams and round panels, although smaller specimens can also be tested. The image shows UCM postgraduate student, Danielle Malherbe, conducting compression tests on compressed earth blocks, stabilised with sugarcane bagasse ash.</p>
UCM student takes part in LIANE Internship in Augsburghttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=2698UCM student takes part in LIANE Internship in AugsburgDanielle Malherbe<p>​​Danielle Malherbe, a Masters student within the Unit of Construction Materials (UCM) of the Department of Civil Engineering, was recently granted the opportunity to attend a two week internship hosted by the Augsburg University of Applied Sciences (AUAS), Germany. The internship formed part of project LIANE (Laboratory for an Integrated African Network for the Built Environment), of which Stellenbosch University (SU)  is one of the partner institutions.</p><p>Project LIANE is funded by the German Federal Ministry of Education and Research and is coordinated by AUAS. Together with SU, the project runs in partnership with Jomo Kenyatta University of Agriculture and Technology (JKUAT) situated in Nairobi, Kenya, and the University of Rwanda (UR) situated in Kigali, Rwanda. The project aims to improve both the sustainability and quality of building and settlement planning in East Africa and gives special attention to energy and resource saving within the building sector. </p><p>Two areas situated in East Africa known as Muhanga and Mlolongo were identified as key planning areas. Danielle worked alongside four AUAS, two JKUAT and two UR students on prospective neighbourhood plans for both Muhanga and Mlolongo. These plans incorporated all facets of the neighbourhoods to ensure that future developments will occur in a sustainable manner. </p><p>The two key planning areas were subdivided into commercial, industrial and residential zones after which proposed building typologies for the various zones were designed. Preliminary designs of the infrastructure, required to link the various zones, were proposed in conjunction with the prospective neighbourhood plans. Two workshops were held during which the plans were presented and discussed. As a representative of UCM en Stellenbosch University, Danielle's specific contribution to the project was the use of sustainable construction materials.</p><p>The five African students were taken on excursions in and around Augsburg as well as in Munich to obtain an improved view on how these cities developed over time. The students also attended a German language course during which they were taught basic language and grammar skills. The two weeks internship allowed Danielle to broaden her views on both sustainable urban development and the different perspectives of the various cultural groups with whom she came into contact.</p>
First PhD Student graduates from UCMhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=2699First PhD Student graduates from UCMBilly Boshoff<p>​Dr John Babafemi is the first student to graduate with a PhD from the Unit for Construction Materials (UCM) at the Department of Civil Engineering. He did his research on the tensile creep of cracked macro synthetic fibre reinforced concrete (MSFRC). This is an important aspect as engineers rely on the contribution of fibres bridging the cracks in MSFRC, but very limited work has been done to verify that the load can be sustained over long periods of time. He found that significant crack widening in cracked MSFRC occurs when subjected to a sustained uni-axial tensile load. This crack widening is however less severe when MSFRC beams are loaded in flexure, which is the more typical application of MSFRC in practise. The question thus remains: how can this time-dependant crack widening be reduced? The answer probably lies in modifying the synthetic fibres.</p>
UCM student investigates local supplementary cementitious materials for more sustainable concretehttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=2790UCM student investigates local supplementary cementitious materials for more sustainable concreteVital Alexandre<p>​​</p><p style="text-align:justify;">A Masters student of the Unit for Construction Materials (UCM), Vital Alexandre, is currently investigating the performance of locally available supplementary cementitious materials (SCM's) when used as cement replacements in a concrete mixture. This is done by assessing the physical and chemical properties of SCM's individually, as well as the plastic state and hardened concrete properties. The main materials he is considering are slag and fly ash, the by-products of the steel manufacturing and coal combustion processes, respectively. The incorporation of these SCM's in concrete reduces the amount of cement required in concrete, as well as beneficiating the waste products of other industrial processes. </p><p style="text-align:justify;">Assessing the physical and chemical properties of the SCM's gives insight into the potential of the materials to be cementitious, as well as to the impact they may have on the concrete matrix. The chemical composition, determined by the Central Analytical Facilities (CAF) at Stellenbosch University, provides a preliminary indication of the potential level of pozzolanicity. Moreover, the morphological data, obtained by scanning electron microscope (SEM) imaging, will be used to describe the behaviour in the concrete matrix, for example the potential impact it may have on the concrete workability and water requirements. Additionally, the pozzolanic activity of the SCM's will be tested directly, by means of the Frattinni method chemical test, and indirectly, by means of the strength activity index.</p><p style="text-align:justify;">The properties investigated whilst the concrete is still in its plastic state, include the workability, setting time, bleeding and evaporation, as well as the plastic shrinkage and settlement. The general consensus is that fly ash will improve the workability of a concrete mixture. Slag on the other hand, may have a lesser effect on the workability; partially due to it having similar particle properties to cement particles. Bleeding and evaporation are essential in determining the sensitivity of SCM's-based concrete mixes to plastic shrinkage cracking and whether additional precautions should be undertaken during the curing process. In addition, the amount of bleeding occurring also gives insight into the degree of interconnection between pores during the initial hydration process. The plastic shrinkage and settlement is investigated using a climate controlled environment. These results are used in tandem with the bleeding and evaporation data to establish the effect of restraints during the early ages of hydration. </p><p style="text-align:justify;">The properties investigated of the concrete's hardened state include compressive and tensile strength, the elastic modulus and durability aspects, in addition to microstructural aspects and the effect of drying shrinkage. The use of SCM's is expected to reduce the early age strength of concrete. However, with the progression of time and effect of secondary hydration reactions, the strength of the concrete containing SCM's might exceed that of the reference mixture. The durability of concrete is typically associated with aggressive agents, such as water, oxygen, carbon dioxide and chloride ions, and the mechanisms by which these substances move through the concrete matrix. The permeability, adsorption and diffusion of concrete are tested using the oxygen permeability test, lime saturated water absorption test time and the chloride conductivity test, respectively. The use of SCM's in concrete has shown to improve the durability, due to refined pore structures and additional hydration products that are formed.</p><p style="text-align:justify;">The microstructure is assessed by using the CT-scanning facilities at Stellenbosch University. The data generated provides information on the pore and air volume, pore distribution and capillary interconnectivity. The results in turn provide an array of information on explaining the improved durability previously mentioned. In addition, the data can also be used in conjunction with the drying shrinkage results to better understand the relationship between the microstructure and volume stability. The overall conclusion is that the microstructure of concrete mixes containing SCM's will be superior to that of a mixture only containing cement as the binder.</p>
UCM Students attend ConMat’15, Canadahttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=2955UCM Students attend ConMat’15, CanadaBernard Le Roux<p style="text-align:justify;">In August 2015 some staff and students of UCM and the Department of Civil Engineering had the opportunity to attend the Fifth International Conference on Construction Materials, ConMat'15, hosted at the Hilton Resort in Whistler, British Columbia, Canada. The conference brought together experts in materials and structures and created a platform where research and innovative solutions for current infrastructure inadequacies could be discussed. ConMat'15 hosted around 200 presentations from nearly 30 countries around the world covering various topics including fibre reinforced concrete, high performance concrete, concrete durability and life cycle costing. </p><p style="text-align:justify;">Research papers by UCM staff and students, Professor Billy Boshoff, Riaan Combrinck, Wibke de Villiers, Bernard Le Roux, Arina Van Noordwyk and John Babafemi, were included in ConMat'15 which focused on aspects of concrete durability, concrete sustainability, fracture mechanics of concrete and the thermal performance of walling systems.</p><p>Apart from the academic experience guests could enjoy the sights that Whistler had to offer. Whistler was the former host of the 2010 Winter Olympics and is situated approximately 125 km north of Vancouver. Whistler is a renowned tourist attraction, characterized by panoramic views of picturesque mountains and forests, state of the art infrastructure and distinctive Canadian architecture. Conference atttendees had the opportunity to enjoy activities such as skiing, golf, gondola rides to the alpine country and mountain biking. Aside from beneficial academic discussions, ConMat'15 provided a great cultural experience as guests had the opportunity to interact with fellow experts from around the world.</p>
UCM Student attends CONCREEP-10 Conference in Viennahttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=3042UCM Student attends CONCREEP-10 Conference in ViennaPieter Daniel Niewoudt<p style="text-align:justify;">​The 10<sup>th</sup> edition of a highly successful conference series (CONCREEP-10) on the Mechanics and Physics of Creep, Shrinkage, and Durability of Concrete and Concrete Structures was held between 21 and 23 September, 2015 at Vienna University of Technology (TU Wien). The first conference started more than half a century ago in Munich (1958) and the main objective of CONCREEP-10 remained true to the original objectives of this conference series, to review and discuss novel efforts in both research and engineering practice on physical origin, prediction and structural effects of time-dependent deformation of concrete.</p><p style="text-align:justify;">Papers written by prominent scientists and engineers from around the world were included in the CONCREEP-10 conference and among these papers were a research paper written by PhD student, Pieter Daniel Nieuwoudt, and his promoter, Professor Billy Boshoff, both of the Unit for Construction Materials (UCM). The paper focussed on modelling the time-dependent pull-out behaviour of hooked-end steel fibres from concrete. Pieter had the privilege to attend this conference in Vienna, thanks to the financial support of UCM's industry partners, namely PPC and THRIP. </p><p style="text-align:justify;">Apart from the academic experience participants of CONCREEP-10 could also experience the culture of Vienna, the capital and the largest city of Austria. Together with its rich musical history and architectural ensembles Vienna provides many activities such as boat rides on the Danube River, tours through the beautiful city, and visits to museums and imperial palaces. The CONCREEP-10 conference allowed Pieter to get up to date with the work being done on the time-dependent behaviour of concrete in both research and engineering practice as well as to experience different cultures as he had the opportunity to interact with participants from around the world.</p>
UCM visits PPC De Hoek Planthttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=3622UCM visits PPC De Hoek PlantRiaan Combrinck<p>​​​UCM member, Riaan Combrinck, and 10 undergraduate Civil Engineering students from Stellenbosch University, visited industry partner PPC at their De Hoek cement plant near Piketberg. The visit started with a presentation to give an overview of both PPC as well as the De Hoek plant. This was followed by a 3 hour guided tour of the plant, including the limestone mining area as well as the production, storage, packing, sales and laboratory areas.  The tour ended with a great lunch before heading back to Stellenbosch. A big thank you to PPC De Hoek for being a tremendous host and for creating a truly memorable visit. </p>
Collaboration between SU’s UCM and Bath University’s BRE CICMhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=3657Collaboration between SU’s UCM and Bath University’s BRE CICMWibke de Villiers<p>The Unit for Construction Materials (UCM) recently hosted colleagues from Bath University's BRE Centre for Innovative Construction Materials (BRE CICM) for a workshop at STIAS, with the purpose of identifying possible areas of research collaboration within innovative construction materials. Bath University is one of Stellenbosch University's Key Partners and future collaboration would be of great value to both institutions. BRE CICM was represented by Prof Andrew Heath, Dr Bhavna Sharma and Dr Kevin Paine, whereas UCM was represented by Prof Billy Boshoff, Dr Riaan Combrinck, Wibke de Villiers and Algurnon van Rooyen.</p><p>Many common interests between the two research units were discovered and possible areas of collaboration that were identified include the self-healing of plastic settlement and shrinkage cracking, developing appropriate standards for alternative masonry units, fibre reinforced concrete and structural applications of alkali activated materials. Initial plans have been made to exchange more information on these topics and collaborate on a number of publications to pave the way for further expansion of the research partnership.</p>
Launch of the Unit for Construction Materialshttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=3829Launch of the Unit for Construction MaterialsLiesel Koch<p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">"We are like concrete," said Prof Billy Boshoff at the official launch of the Unit for Construction Materials in the Department of Civil Engineering, Stellenbosch University. "Concrete consists of different materials, some more expensive, some unpredictable, but together they make concrete. No ingredient is more important than the other one, because if you take one ingredient out, the concrete will not work." Hereafter he acknowledged all present - individuals, institutes and industry - for their important roles in the Unit.</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">The Unit for Construction Materials (UCM) was officially launched on 13 April 2016 at a dinner held appropriately in the new concrete laboratory. The event was well attended and numerous prominent figures in the construction industry were present, including Hanli Turner and John Sheath, the President and the CEO of the Concrete Society of Southern Africa (CSSA) respectively, and Bryan Perrie, the Managing Director of The Concrete Institute (TCI).</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">The UCM strives to be a centre of excellence and a top institute for construction materials in South Africa for teaching, research and consulting. Research and student training are at the core of the UCM. During his speech, Prof Boshoff highlighted the importance of industry collaboration and partnership. Special emphasis was put on the fact that research must have both academic value and relevance for the industry on the short or long term. Providing a consultation service to the industry, especially where these services at not available at commercial laboratories, is also a high priority the UCM.</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">The UCM is interested in all aspects of construction materials, but the four main areas of the current focus is:</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">* Eco-friendly construction materials</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">* Fibre reinforced concrete</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">* Fresh and young concrete</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">* High performance concrete</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">More information about the UCM can be found at <a href="/ucm" style="color:#666666;">www.sun.ac.za/ucm</a> or <a href="mailto:bboshoff@sun.ac.za" style="color:#666666;">bboshoff@sun.ac.za</a>.</p><p style="color:#333333;font-family:'noto sans', helvetica, sans-serif;font-size:12px;line-height:20px;background-color:#ffffff;">Caption: From the left: Dr Riaan Combrinck (UCM), Prof Eugene Cloete (Vice-Rector Research), Prof Billy Boshoff (Head UCM), Ms Wibke de Villiers (UCM) and Prof Hansie Knoetze (Dean: Engineering).</p>