Condition assessment of a Johannesburg skyscraper

This paper presents a condition assessment conducted on a Johannesburg skyscraper. It had become apparent that concrete spalling occurred in areas of the top 11m of the Southern and Western facades of the reinforced concrete skyscraper constructed in the 1970’s. However, the extent of the problem was unknown. The only information available were two photographs showing spalled concrete and severely corroded reinforcement bars. Some literature search pertaining to the structure was conducted after which, visual inspection and mapping of spalled areas and cracks were conducted. This was followed by a cover meter survey, a half-cell potential survey, and the removal of 20 (twenty) cores for laboratory testing. It was found that the typical problems associated with carbonation and insufficient cover resulted in the corrosion of reinforcement which then led to the spalling observed

Sumber Daya Manusia dan Manajemen Organisasi dalam Pelaksanaan Upaya Kesehatan Masyarakat di Dua Kecamatan di Jakarta Timur

Latar belakang: Prioritas dan fokus kebijakan kesehatan yang berkembang saat ini makin menunjukkan bahwa program public health adalah sama atau bahkan jauh lebih penting daripada tekanan pengobatan dalam meningkatkan status kesehatan penduduk. Meski pemerintah telah meminta puskesmas dan kelurahan fokus pada pengembangan dan pelaksanaan program-program public health, sedikit studi melaporkan kemampuan organisasi pemerintah yang benar-benar mengerjakan fungsi ini. Penelitian ini mengevaluasi hubungan capaian program public health dan apakah capaian itu didukung oleh ketersediaan sumber daya manusia dan kapasitas implementasi program dari organisasi pemerintah. Metode: Data berasal dari “standar pelayanan minimal” kesehatan masyarakat dan “perilaku hidup bersih dan sehat” (PHB), survei dan wawancara mendalam terhadap 46 responden dari 17 puskesmas dan 14 kelurahan di dua kecamatan - Matraman dan Jatinegara - di Jakarta Timur. Hasil: Penelitian ini menemukan bahwa indikator capaian kesehatan di daerah penelitian di kota besar seperti Jakarta adalah lebih rendah dari capaian rata-rata nasional meskipun memiliki ketersediaan sdm yang memadai. Selain itu, kapasitas administrasi dan manajemen proses implementasi di lapangan tidak seperti yang diharapkan. Simpulan: Studi ini menunjukkan paradoks antara ketersediaan sumber daya dan kapasitas yang lemah dalam kolaborasi lintas sektoral dan dalam manajemen implementasi program. Kami mendiskusikan 3 faktor penting yang harus menjadi perhatian dalam pengembangan dan implementasi upaya public health di Jakarta. Pertama, peran lintas sektoral yang jadi kewenangan dari walikota harus mendapat advokasi yang besar dari masyarakat public health. Kedua, administrator kelurahan memiliki kapasitas manajemen implementasi agar program-program dirasakan oleh penduduk setempat. Ketiga, puskesmas memiliki sdm dengan kemampuan manajerial dan bekerja sama dengan sektor lain yang bekerja fokus untuk upaya kesehatan masyarakat

Evaluation of reactivity indexes and durability properties of slag-based eopolymer concrete incorporating corn cob ash

The method of determining the quantities of geopolymer concrete (GPC) ingredients to attain the required and specifiable characteristics is complex owing to the involvement of more variables compared with Portland cement concrete (PCC) systems. Therefore, this study evaluated the hydraulic responses and chemical resistance of GPC produced with supplementary cementitious materials (SCMs), ground granulated blast furnace slag (GGBFS) and corn cob ash (CCA) at ambient curing conditions. Corn cob was dehydroxylated at 600 �C and used as a partial replacement for GGBFS at 0, 20, 40, 60, 80, and 100%. The activators used were 12, 14 and 16 M concentration (M) of both sodium silicate (SS) and sodium hydroxide (SH). The chemical compositions of individual and mixed binders were analyzed, while the chemical moduli of each and blended binder were examined and evaluated based on the significant reactive oxides, hence resulting in the evaluation of reactivity indexes (RIs). Moreover, the compressive strength was predicted based on the RIs and mix design proportions (MDPs) of the blended concrete, while the durability properties of each concrete sample were investigated. The results indicated that the oxide compositions of GGBFS and CCA influenced the compressive strength of GPC produced. Compared with the experimental results, the predictive compressive strengths based on the RIs and the MDPs yielded a high precision with 95% ‘‘R2”. Furthermore, the incorporation of both GGBFS and CCA increased the durability of GPC produced against sulfate attacks. Ultimately, the model equations developed by this study can be beneficial in the refinement of mix designs of both GPC and conventional concrete incorporating SCMs provided the oxide compositions of the elements are obtained

Assessment of activity moduli and acidic resistance of slag-based geopolymer concrete incorporating pozzolan

The environmental impact of Portland cement production and utilization in the construction sector has led to the global call for the use of eco-friendly construction materials for the production of cleaner and sustainable products. Therefore, this study explored agro-industrial wastes, slag and corncob ash, for the production of geopolymer concrete (GPC). Corncob was dehydroxylated at 600 �C for 3 h and partially used as a replacement for slag at 0%, 20 %, 40 %, 60 %, 80 %, and 100 %. A 12 M, 14 M, and 16 M of both sodium silicate (SS) and sodium hydroxide (SH) were used as activators. The chemical moduli of each and mixed binder were quantified and evaluated based on the major reactive oxides, hence leading to the evaluation of reactivity indexes (RIs). Moreover, the RIs and mix design properties (MDPs) of concrete were used for the prediction of flexural strength while the chemical resistance of each concrete sample was investigated. Compared with the experimental results, the predictive flexural strengths based on the RIs and the MDPs yielded a high precision with R2 ranging from 88–92 % at 7–90 days, respectively. Moreover, the GPC, unlike Portland cement concrete (PCC), resisted the more acidic attack. Therefore, the use of GGBFS�CCA blended concrete would be more advantageous in a highly acidic environment than PCC. Ultimately, the models proposed by this study can be useful in the concrete mix design procedure for the flexural strength development of GPC incorporating agro-industrial provided the oxide compositions of each and mixed material were obtained

Similarities and differences of pumping conventional and self-compacting concrete

In Practice, Self-Compacting Concrete (SCC) is Considered as a Simple Extension of Conventional Vibrated Concrete (CVC) When Pumping is Concerned. the Same Equipment, Materials, Pumping Procedures and Guidelines Used for CVC Are Applied When Pumping SCC. on the Other Hand, It Has Been Clearly Shown that the Rheological Properties and the Mix Design of SCC Are Different Than CVC. Can the Same Pumping Principles Employed for CVC Be Applied for SCC? This Paper Compares the Some Published Results of Pumping of CVC with Those for SCC. a First Striking Difference between Pumping of CVC and SCC is the Flow Behaviour in the Pipes. the Flow of CVC is a Plug, Surrounded by a Lubricating Layer, While during the Flow of SCC, Part of the Concrete Volume itself is Sheared Inside the Pipe. as a Result, the Importance of Viscosity Increases in Case of SCC. Due to the Low Yield Stress of SCC, the Behaviour in Bends is Different, But Quite Complex to Study. Due to the Lower Content of Aggregate and Better Stability of SCC, as It is Less Prone to Internal Water Migration, Blocking is Estimated to Occur at Lower Frequency in Case of SCC. © RILEM 2010

BUILDING A SUSTAINABLE WORLD: ECONOMY INDEX OF GEOPOLYMER CONCRETE

Geopolymer concrete offers a considerable solution not only to the environmental problem but also to the structural deterioration confronting the world. But, limited or no study is found on its cost implications. Consequently, this study evaluates the production cost and the economy index of geopolymer concrete (GPC) and compares it with the Portland cement concrete (PCC). Corncob ash (CCA) and ground granulated blast furnace slag (GGBFS) were used as source materials in the production of geopolymer concrete. Alkaline liquids were prepared to obtain 12 molar concentrations. The concentration was used to activate the source materials. Grade 30 concrete (M30) was adopted as a mix design proportion. GGBFS was replaced by CCA in varying percentages as 0%, 20%, 40%, 60%, 80%, and 100%. The research findings reveal that GPC is 27.71% lesser than the PCC in terms of production cost while the economy index of GPC is higher than the PCC for the same grade of concrete. The results infer that GPC is cheaper and more viable than the PCC. Thus, geopolymer concrete proves to be an innovative product and appears to be a feasible solution not only to the environmental and structural deteriorating problems but also to the problem of high cost of Portland cement in the construction industr

Riparian Management in Intensive Grazing Systems for Improved Biodiversity and Environmental Quality: Productive Grazing, Healthy Rivers

Within high rainfall intensive grazing systems of southern Victoria, riparian zones are often degraded due to vegetation clearing, stock access and inappropriate farm management. Streams in these landscapes often have poor water quality and reduced biodiversity due to degraded terrestrial and aquatic ecosystems. Improved management of riparian zones depends on developing tools and practices for integration into productive grazing systems. This paper describes the approaches used and the tools developed in the ‘Productive Grazing, Healthy Rivers: Improving riparian and in-stream biodiversity’ project

Quality Management in Construction Project: Empirical Study of Covenant University Sports Complex

The acceptable level of quality in construction projects has long been a problem. Significant resources are wasted on construction projects because of inefficient or non-existent quality management procedures. Therefore, this study evaluates the quality management and the quality grading practices in the construction project with emphasis on the Covenant University Sports Complex. The quantitative research strategy and questionnaire survey were used as the main data collection instrument for soliciting information from the project participants in order to determine the best key for quality management practice. Moreover, an ultrasonic pulse velocity tester was engaged to assess and evaluate the conditions of concrete structural members. It was found out that management commitment to quality is the most key for effective quality management practices in the construction project. In addition, the ultrasonic pulse velocity (UPV) test carried out on the randomly selected structural members varied in the range 4.2km/sec to 4.6km/sec. From this, it is inferred that the quality grading and homogeneity of concrete in the tested reinforced concrete columns, beams and slabs fall in the range of “good to excellent concrete”. The findings would assist project participants in implementing an efficient quality grading and management while executing construction projects

Management Practices Adopted by Administrators of Children Library Section of College of Education for Enhancing Information and Communication Technology: Implication for Policy and E-Counselling

Management practices adopted by the colleges of education administrators who are primarily posted to children library section in enhancing ICT seem to be poor. The study examined the challenges associated with the management practices. We adopted a descriptive research design. A total of 73 respondents (Seven Children Library Administrators and 66 ICT officers) were used as the study sample. One instrument was used for collection of data. The respondents were administered the instrument with the help of five brief research assistants. Data analysis was completed using mean and standard deviation for research questions and z-test was used to test the hypotheses. The researchers found that library administrators are facing some challenges in enhancing ICT in the Children library sections of Colleges of Education. It was also found that there was no significant difference between the Children library administrators and the ICT officers on the two hypotheses. The researchers concluded that Children library administrators should adopt certain strategies that will curb the challenges facing the enhancement of ICT in Children libraries for the effectiveness of the college libraries