To future-proof alkali-activation technology, there is a need to look beyond well-established precursors such as fly ash and blast furnace slag, due resource competition, geographical distribution technical limitations. Clay minerals are abundant diverse aluminosilicate resources available around the world. However, mineralogical complexity amongst most common 1:1 (kaolinite, halloysite) 2:1 (montmorillonite, illite) clay minerals, practical issues workability, their use has been more...

Self-healing concrete based on calcium carbonate precipitation induced through bacterial activity has been investigated in recent years by teams around the world. For first time, optimisation of self-healing performance was considered terms number spores required, concentration and composition nutrients precursors, whether a two-component system likely to efficiently produce concrete. This information is required if efficient cost-effective systems are be implemented. this research, coated...

Partially replacing cement clinkers with activated clays is one of the most promising routes to decarbonise industry and tackle climate change crisis. This study systematically investigated impact mechanochemical activation on physicochemical properties kaolinite, muscovite montmorillonite clays, including particle size distributions, morphologies, bulk surface chemical structures. The results suggest that treatment particularly efficient for improving pozzolanic activity 2:1 (i.e....

Using alkali activation, un-calcined soils have potential as precursors for low carbon, cost, geopolymer-stabilised construction materials. This technology has been recently promoted a lower impact alternative to cement stabilisation walling materials in around the world. There is lack of fundamental understanding activation montmorillonite and illite, which, along with kaolinite, are clay minerals commonly found soils. Kaolinite, 1:1 mineral, shown form crystalline hydrosodalite when...

In this paper, the results of static and dynamic hygric tests on 114 unfired clay masonry samples are presented. Samples were prepared as Compressed Earth Blocks (CEB) or plasters. The variability soils, soil density preparation methods investigated to determine their influence moisture buffering capacity, water vapour permeability sorption isotherms. Moisture Value (MBV) was measured according Nordtest protocol could therefore be compared conventional materials. indicate has a much higher...

Characterization of alkaliphilic Bacillus species for spore production and germination calcite formation as a prelude to investigate their potential in microcrack remediation concrete.Conditions, extent timing endospore was determined by dark-field light microscopy; induction kinetics were assessed combining reduction optical density with refractile bodies phase-contrast microscopy. pseudofirmus selected from several the most suitable isolate. Levels calcium carbonate precipitated vitro B....

Carbon fibre reinforced cement-based sensors offer a potential low-cost and high-performance alternative to externally applied for health monitoring of concrete structures. This paper focuses on the moisture dependence bulk conductivity carbon with contents 0.1–1.5 vol%. Under two-point AC impedance spectroscopy at frequencies 1 Hz–10 MHz, electrode polarization (EP) process, an electrical double layer process (EDLP), Maxwell-Wagner type interfacial (MWP) were identified. While reducing...

Costs associated with the encapsulation process of bacterial spores continue to be a limiting factor for commercialisation self-healing cementitious materials. The feasibility using air-entraining admixtures (AEAs) as an economical and straightforward method was evaluated heal cracks (∼0.50 mm) that were formed at early (28 days) or later age (9 months). Three AEAs, commonly used in concrete industry, compared successfully proven protection (i.e., via aerated granules (ACGs)). In this...

The objective of this study was to investigate the contribution ethnicity (African American vs European/other ancestry), family religious affiliation, involvement, and values, risk alcohol cigarette use in adolescent girls; estimate genetic shared environmental effects on involvement values. Telephone interviews were conducted with a sample female like-sex twin pairs, aged 13–20 (n = 1687 including 220 minority pairs), as well one or both parents twins 11–20 2111 families). These data,...

This study determined the impact of oxygen and water on crack healing performance bacteria-based self-healing cementitious composites (BBSHCCs). Oxygen are considered essential to BBSHCCs using non-ureolytic bacteria, but in practice, availability either, for even short periods time, cannot be guaranteed immediate aftermath a forming. In this study, four regimes, (i) daily wet-dry cycle, (ii) weekly (iii) semi-submerged, (iv) deposition medium, were utilised compare BBSHCCs. Furthermore, an...

Integrated cement-based sensors offer an economic alternative to extrinsic for health monitoring applications in concrete structures due their high strength cost ratio, geometrical versatility, low shrinkage, and natural compatibility. Nonetheless, performance under in-service conditions were lack of investigations. While the piezoresistivity (change resistance with stress) has been commonly used mechanical sensing, piezopermittivity capacitive reactance is rarely characterized. Exploiting...

Interest in traditional unfired clay building materials has grown the UK recent years. Although use of vernacular techniques, such as cob, adobe and rammed earth, have raised profile earthen architecture, wider impact on modern construction is likely to come from innovations extruded masonry units. A large driver behind move significant reduction embodied energy when compared with fired bricks concrete blockwork, passive environmental control provided by clay. This paper summarises results...

Rammed earth is an accessible, sustainable and increasingly popular building material. Owing to a lack of research, current design standards for rammed have taken conservative stance on material attributes like shear strength. Evaluating the strength particularly important in seismic areas because material's high mass, low ductility propensity fail shear. Shear test methods designed other materials typically been used practice determine earth. In this research guidance available was compared...