Crack spacing has been identified as an important parameter in predicting the crack widths in reinforced concrete (RC) structures. An experimental program has been conducted to investigate the crack spacings when reinforced concrete beams are subjected to both axial tension and flexure. The stochastic nature of cracking behavior makes the experimental program complicated. A large sample size of the crack spacing data was recorded, in order to give a statistical overview. Recent studies in the literature were used to verify the experimental results. The existing crack spacing prediction models have been developed based on different theoretical approaches, namely bond-slip, no-slip, and combined approaches. In this study, Eurocode 2, Model Code 2010, Japanese Code, Eurocode 2 with German Annex and Beeby's crack spacing models were selected, as they represent each theoretical approach. Experimental results of this study and from selected literature were compared with the aforementioned prediction models. Japanese Code gave better predictions for axial tensile tests. For the four-point bending test, all the calculation models gave good agreement with the results, except for Eurocode 2 with German Annex.

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There has been a significant movement in the past decades to develop alternative sustainable building material such as geopolymer cement/concrete to control CO2 emission. Industrial waste contains pozzolanic minerals that fulfil requirements to develop the sustainable material such as alumino-silicate based geopolymer. For example, industrial waste such as red mud, fly ash, GBFS/GGBS (granulated blast furnace slag/ground granulated blast furnace slag), rice husk ash (RHA), and bagasse ash consist of minerals that contribute to the manufacturing of geopolymer cement/concrete. A literature review was carried out to study the different industrial waste/by-products and their chemical composition, which is vital for producing geopolymer cement, and to discuss the mechanical properties of geopolymer cement/concrete manufactured using different industrial waste/by-products. The durability, financial benefits and sustainability aspects of geopolymer cement/concrete have been highlighted. As per the experimental results from the literature, the cited industrial waste has been successfully utilized for the synthesis of dry or wet geopolymers. The review revealed that that the use of fly ash, GBFS/GGBS and RHA in geopolymer concrete resulted high compressive strength (i.e., 50 MPa–70 MPa). For high strength (>70 MPa) achievement, most of the slag and ash-based geopolymer cement/concrete in synergy with nano processed waste have shown good mechanical properties and environmental resistant. The alkali-activated geopolymer slag, red mud and fly ash based geopolymer binders give a better durability performance compared with other industrial waste. Based on the sustainability indicators, most of the geopolymers developed using the industrial waste have a positive impact on the environment, society and economy.

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The flange inspection associated with piping on offshore production facilities is a time-consuming activity as the flanges should physically be opened in order to perform close visual inspections. In order to sustain maintenance integrity, a number of inspections are allocated for a subsystem based on factors such as: condition of the medium flowing in the line, risk perception of the pipeline system, and the date of installation. Inspection teams recommend inspections based on the data, experience, and exposure to offshore production facilities, as well as the intuition and intentions of those individuals involved with inspection planning and with carrying out implementation during the preventive maintenance shutdowns. However, there is a tendency for the operating company representatives to raise queries with the contractor company representatives about the number of flanges to be opened during the preventive maintenance shutdown as flange inspection consumes a considerable portion of time and resources. Hence, it is vital to interpret sensibly the importance of recommending close visual inspections for flanges if the maintenance integrity is to be sustained. This study focuses on analyzing the historical data limited to flanges on flowlines over the last fifteen years. The final results provide a snapshot of the present status of the flanges of the production facility.