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This research considers the compressive strength, embodied CO 2, embodied energy and binder intensity of hydraulic lime-pozzolan concretes, in comparison with those of Portland-cement based concretes of equivalent 28-day compressive strength. Production of a lime-pozzolan concrete with a 28-day cube strength of approximately 50 MPa and an elastic modulus of 20GPa has demonstrated the feasibility of producing modern, structural grade hydraulic lime-pozzolan concretes. Furthermore, construction and testing of two reinforced lime-pozzolan concrete beams has demonstrated the possibility of producing structural elements with a finished appearance and flexural behaviour similar to Portland cement concrete. This paper reflects on the value of this new material's technological progress in the context of the industry wide search for low carbon cements. Results of the research reported in this paper demonstrate that the use of aluminosilicate byproducts, specifically ground granulated blastfurnace slag and silica fume, in combination with naturally hydraulic lime can realise savings in environmental impact; but that the savings are both future-orientated and highly dependent on the boundaries of the analysis. When considering only the secondary impacts of ground granulated blastfurnace slag and silica fume production, a ternary combination was observed to result in a lime-pozzolan concrete with a 28-day cube strength of 33MPa and an embodied-CO 2 of 95 kgCO 2 /m 3 , 64% lower than a CEMI, and 41% lower than a CEMIII/A concrete of equivalent strength. Both mass and economic allocation procedures were, however, shown to have a very detrimental effect on the environmental credentials of silica fume and thus also on hydraulic lime-concretes containing this pozzolanic addition. It is recognised that technical performance alone cannot be used to assess or compare the merits of any new material. This paper focus on the production, environmental impact and long-term availability of individual constituents of this novel binder, with a view to addressing important questions about the viability and desirability of reproducing this novel cementitious system in a commercial setting. Such information is acknowledged to be critical in the dialogue about the potential adoption and development of this emerging binder technology.

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A novel, compact mathematical formulation is presented to describe the dynamic rocking response of single and double block systems subjected to gravity and/or ground excitation. The derivation of the closed-form solutions for impact and motion is based on the Euler-Lagrange equation and the conservation of angular momentum, and combines all the different cases of possible block relative rotating and impact modes (16 in total) into a single set of equations without the need of transient expressions. The derived equations that describe the impact modes are the equivalent to the expression derived by Housner and depend on the angular velocity of the blocks before impact. The analytical model is integrated numerically via an ad hoc algorithm and its reliability & accuracy are verified after various self-consistency tests and comparisons with the literature. In addition, several shaking table experiments were conducted in EQUALS laboratory in Bristol, setup constructed to test free and forced rocking motion of single and double block configurations. The error margins of the measurements are determined, and the extracted data are in good agreement with the numerical results for most examined cases. The ideal Housner restitution coefficient of single block impact to a rigid base is adjusted to match experimental conditions, and it is found to be correlated with the block aspect ratio. The forced rocking of a two-block system is shown to exhibit numerous different response patterns depending on the excitation conditions. The integrated model is finally applied to produce normalised overturning maps for double block systems, subjected to singlepulse sine inputs, which uncover the existence of a fractal-type behaviour. This previously unsuspected trait of multi-block systems is reminiscent of the chaotic behaviour exhibited by a classical double pendulum and suggests that the risk of overturning can only be evaluated on a probabilistic sense.

The critical T-sections of multi-joist timber concrete composite (TCC) floors must be designed at ultimate for support shear force and midspan moment, both of which are influenced by transverse sharing, but to different extents. Prior experimental work has investigated only support reaction sharing and only up to serviceability loads. The present experimental study builds on that status quo by quantifying also moment sharing, via strain gauge layouts at quarter-span and mid-span, along with reaction sharing via load cells at the supports of a multi-joist TCC specimen, over the entire load range up to failure. Use of steel mesh connectors bonded into hardwood laminated veneer lumber joists, and near geometric resemblance to a real building TCC floor recently built in London, were novel features of the specimen. The results show that midspan moment and reaction sharing both vary nonlinearly with load, but in distinctly different ways from each other (with up to almost 20% difference observed between them), in the progression between the uncracked, cracked and connection ductility regimes. In this approach reliable assessment of moment sharing depends on the quality of the recorded strains. Accordingly, the strain data were shown to be of high quality by converting these data to internal stress resultants that were then found to satisfy longitudinal equilibrium. It is concluded that this strain gauge layout is useful for future work aimed at building a database of transverse sharing of moments in TCCs.