Strength Variation of OPC-Saw Dust Ash Composites with Percentage Saw Dust Ash

This work investigated the variation of OPC-Saw Dust Ash (SDA) composites strength with percentage SDA. 231 concrete cubes, 231 sandcrete cubes, and 231 soilcrete cubes of 150mm x 150mm x 150mm were produced at percentage OPC replacement with SDA of 0% (control), 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% and crushed to obtain their compressive strengths at 3, 7, 14, 21, 28, 50, and 90 days of curing. For concrete, the 90-day strength values decreased from 28.00N/mm2 at 5% SDA to 25.60N/mm2 at 15% SDA to 20.50N/mm2 at 35% SDA to 15.80N/mm2 at 50% SDA, while the control value was 27.00N/mm2. The 90-day strength values also decreased from 11.50N/mm2 at 5% SDA to 5.40N/mm2 at 50% SDA for sandcrete while the control value was 11.10N/mm2. Soilcrete strength values decreased from 9.70N/mm2 at 5% SDA to 4.50N/mm2 at 50% SDA while the control value was 9.50N/mm2. The results suggest that, with good quality control of the concreting process, 5% to 25% OPC replacement with SDA could be suitable for general reinforced concrete works, 25% to 40% for minor works in concrete, and 45% to 50% for plain concrete works. Also, 5% to 20% OPC replacement with SDA could be used for light load-bearing sandcrete and soilcrete works, while 25% to 50% could still be suitable for non-load-bearing works. Keywords: Blended cement, Composites, Compressive strength, Concrete, Sandcrete, Saw dust ash, Soilcrete

AUDIENCE PERCEPTIONS AND ATTITUDES ON MEDIA COVERAGE OF HIV AND AIDS PANDEMIC IN LIMPOPO PROVINCE, SOUTH AFRICA

South Africa has the highest HIV and AIDS prevalence in the world despite theefforts by all stakeholders to mitigate its spread and start reversing the rate of newinfections. It is also evident that the general public depend on the media for theirinformation and educational needs concerning the disease. However, HIV andAIDS prevalence rate is still very high in Limpopo province. The HIV and AIDSincidence rate is equally high in South Africa, as well as in the Limpopo province.This study investigates audience perceptions and attitudes towards mediacoverage of the HIV and AIDS and factors fuelling the pandemic in the province.A detailed questionnaire was used to collect data from residents of Bochum inCapricorn District, Thohoyandou in Vhembe district, Phalaborwa in Mopanidistrict, and Jane-Furse in Sekhukhune district of the Limpopo province. Thestudy indicated that most residents in the province have positive perceptions aboutmedia coverage of the pandemic. In spite of the extensive media coverage, theirattitudinal responses were not quite encouraging. The study highlighted that themajor factors influencing audience attitudinal response to media coverage of thepandemic include: poverty, rape, Sexually Transmitted Diseases (STDs), alcoholand drugs, and unplanned teenage pregnancy. This study recommends that anyHIV and AIDS mitigation strategy in the province should take into consideration the aforementionedfactors and that the media should consistently and adequatelyreport on the pandemic as one of the development challenges of the province