Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Utilisation of municipal solid waste incinerator (MSWI) fly ash with metakaolin for preparation of alkali-activated cementitious material

For many years industrial companies have fought to protect steel reinforced concrete from corrosion. The prime causes of corrosion in concrete include salt, chloride and de-icing treatments. The salt seeps into the concrete and erodes the steel reinforcing bar (rebar) causing cracks and spalling in the concrete and eventually the potential for failure of the structure. One very effective, long-term solution is metal or thermal spraying the concrete with zinc or a variety of zinc alloys. This is a technology that protects or extends the life of a wide variety of products in the most hostile environments.

Cathodic protection of steel in concrete.

Effect of silica fume on the mechanical property and hydration characteristic of alkali-activated municipal solid waste incinerator (MSWI) fly ash

Based on construction dates and observed time to corrosion induced damage, the future need for repair of reinforced concrete motorway bridges in The Netherlands is predicted. Due to the age distribution and in particular the relatively short life of conventional repairs, the need for maintenance will increase steeply over the next few decades. It appears that a back log of postponed maintenance exists, which aggravates the problem. This steep rise may be mitigated by the application of various modern techniques for assessment, prevention, monitoring, and protection, that each have a good track record but are not widely used. Various factors that oppose the application of such innovations in the area of concrete maintenance are discussed.

Non‐traditional assessment and maintenance methods for aging concrete structures – technical and non‐technical issues

Shrinkage behaviour, early hydration and hardened properties of sodium silicate activated slag incorporated with gypsum and cement

Predicting degradation of the anode–concrete interface for impressed current cathodic protection in concrete

Due to the corrosion of steel in reinforced concrete structures, the concrete with low water-cement ratio (w/c), high cement content and large cover thickness is conventionally used for prolonging the passivation period of steel. Obviously, this conventional approach to durable concrete structures is at the sacrifice of more CO2 emission and natural resources through consuming higher amount of cement and more constituent materials, which is against sustainability. By placing an economically affordable conductive mesh made of carbon fibre or conductive polymer fibre in the near surface zone of concrete acting as anode we can build up a cathodic prevention system with intermittent low current density supplied by e.g. the solar cells. In such a way, the aggressive negative ions such as chloride, carbonate and sulphate can be stopped near the cathodic (steel) zone. Thus the reinforcement steel is prevented from corrosion even in the concrete with relatively high w/c and small cover thickness. This conductive mesh functions not only as electrode, but also as surface reinforcement to prevent concrete surface from cracking. Therefore, this new type of covercrete has hybrid functions. This paper presents the theoretical analysis of feasibility of this approach and discusses the potential durability problems and possible solutions to the potential problems.

http://publications.lib.chalmers.se/records/fulltext/168731/local_168731.pdf

Covercrete with hybrid functions - A novel approach to durable reinforced concrete structures

A rechargeable cement-based battery was developed, with an average energy density of 7 Wh/m2 (or 0.8 Wh/L) during six charge/discharge cycles. Iron (Fe) and zinc (Zn) were selected as anodes, and nickel-based (Ni) oxides as cathodes. The conductivity of cement-based electrolytes was modified by adding short carbon fibers (CF). The cement-based electrodes were produced by two methods: powder-mixing and metal-coating. Different combinations of cells were tested. The results showed that the best performance of the rechargeable battery was the Ni–Fe battery, produced by the metal-coating method.

Rechargeable Concrete Battery

Impressed current cathodic protection (ICCP) is an electrochemical method to prevent or stop corrosion of steel reinforcement in concrete structures. The use of this technique is limited although it has been proven to be effective. One of the reasons is the high cost of anode material, commonly titanium anode. Hence there is a need for alternative anode materials to lower the cost and at the same time to improve the performance of the ICCP system through design. This paper reviews carbon fiber reinforced polymer (CFRP) as an anode for ICCP systems in concrete and discusses the degradation mechanism and operating conditions of the anode. It also gives an overview of the performance of CFRP as an anode material, from laboratory experiments to field operation.

/pdf/application-of-cfrp-as-anode-in-cathodic-protection-for-3z3md0bl2j.pdf

Emma Qingnan Zhang

Papers

Shrinkage behaviour, early hydration and hardened properties of sodium silicate activated slag incorporated with gypsum and cement

Predicting degradation of the anode–concrete interface for impressed current cathodic protection in concrete

Covercrete with hybrid functions - A novel approach to durable reinforced concrete structures

Rechargeable Concrete Battery

Application of CFRP as anode in cathodic protection for steel reinforced concrete – a review