The environmental pollution in urban areas is one of the causes for poor indoor air quality in buildings, particularly in suburban areas. The development of photocatalytic construction materials can contribute to clean the air and improve sustainability levels. Previous studies have focused mainly in cement and concrete materials, disregarding the potential application in historic buildings. In this work, a photocatalytic additive (titanium dioxide) was added to mortars prepared with aerial lime, cement and gypsum binders. The main goal was to study the way that microstructural changes affect the photocatalytic efficiency. The photocatalytic activity was determined using a reactor developed to assess the degradation rate with a common urban pollutant, NO x . The laboratory results show that all the compositions tested exhibited high photocatalytic efficiency. It was demonstrated that photocatalytic mortars can be applied in new and old buildings, because the nanoadditives do not compromise the mortar hardened state properties.

In a society with a high growth rate and increased standards of comfort arises the need to minimize the currently high energy consumption by taking advantage of renewable energy sources. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction of the use of heating and cooling equipment, using only the energy supplied by the sun. However, the incorporation of PCMs in mortars modifies its characteristics. The main purpose of this study was the production and characterization of mortars with incorporation of two different PCMs. Specific properties of two PCMs, such as particle size, shape, and enthalpy, were determined, as well as the properties of the fresh and hardened state of the mortars. The proportion of PCM was 0, 10, 20, and 30% of the total mass of the solid particles. In order to minimize some problems associated with shrinkage and consequent cracking of the mortars, the incorporation of polyamide fibers and superplasticizer was tested. It was possible to observe that the incorporation of PCMs in mortars caused differences in properties such as compressive strength, flexural strength, and shrinkage. Even though the incorporation of PCM microcapsules resulted in an increase in the shrinkage, it was possible observe a significant improvement in mechanical properties.

h i g h l i g h t sMix design of fly ash foam geopolymer. Mixtures with 0.1 W/(m K) therm. conductivity and a 6 MPa comp. strength were achieved. Foaming agents cost represent less than 10% of foam geopolymer cost. a b s t r a c tThis study has investigated the joint effect of several mix parameters on the properties of foam geopolymers. The mix parameters analysed through a laboratory experiment of 54 different mortar mixes were, sodium silicate/sodium hydroxide mass ratio (2.5, 3.5, 4.5), activator/binder mass ratio (0.6, 0.8, 1.0), chemical foaming agent type (hydrogen peroxide (H 2 O 2 ) and sodium perborate (NaBO 3 )) and foaming agent mass ratio content (1%, 2%, 3%). Properties, SEM and FTIR analysis and cost analysis are included. The results show that the sodium perborate over performs hydrogen peroxide leading to a lower overall thermal conductibility of foam geopolymers. Mixtures with a low thermal conductivity of around 0.1 W/ (mÁK) and a compressive strength of around 6 MPa were achieved. The cost analysis show that the foaming agents are responsible for a small percentage of foam geopolymers total cost being that the alkaline activators are responsible for more than 80%.

h i g h l i g h t s Twelve different mortars were developed with phase change material incorporation. The aim of this study was evaluate the effect of the high temperatures on mortars. The exposure to high temperatures leads to a decrease in the mechanical strengths. The behavior to high temperatures of the PCM mortars is similar to reference mortars.

An estimated 1000 million tyres reach the end of their useful lives every year and 5000 millions more are expected to be discarded in a regular basis by the year 2030. Up to now a small part is recycled and millions of tyres are just stockpiled, landfilled or buried. This paper presents results about the properties and the durability of HPC with partial replacement of sand by tyre rubber wastes. Fly ash and metakaolin are used as partial cement replacement. The durability performance was assessed by means of capillary water absorption and resistance to sulphuric acid attack. The results show the existence of a synergetic effect between fly ash and metakaolin that minimizes the strength loss associated to the use of rubber waste. Results also show that is possible to use rubber waste up to 15% and still maintain a high resistance to acid attack. The mixes with 45% fly ash and 15% metakaolin show a much higher resistance to sulphuric acid attack than the reference mix independently of the rubber waste content.

In a society with a high growth rate and increased standards of comfort arises the need to minimise the currently high-energy consumption by taking advantage of renewable energy sources. The mortars with incorporation of phase-change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction in the use of heating and cooling equipment, using only the energy supplied by the sun. However, the incorporation of phase-change materials in mortars modifies its characteristics. The main purpose of this study was the production and characterisation in the fresh and hardened state of mortars with incorporation of different contents of PCM in mortars based in different binders. The binders studied were aerial lime, hydraulic lime, gypsum and cement. For each type of binder, different mortars were developed with different content of PCM. The proportion of PCM studied was 0, 20, 40 and 60% of the mass of the sand. It was possible to observe that the incorporation of PCM in mortars caused differences in properties such as workability, microstructure, compressive strength, flexural strength and adhesion.

This paper analyzed the effect of different fibres on the residual compressive strength, the ultimate load and flexural toughness, the failure pattern and the fracture energy of self compacting high performance concrete (SCHPC) after exposure to various high temperature. The micro polypropylene fibre (PP fibre) could mitigate the spalling of SCHPC member significantly, but did not show clear effect on the mechanic properties of concrete. The macro steel fibre (SF) reinforced SCHPC showed higher flexural toughness and ultimate load before and after high temperatures. The mechanical properties of hybrid fibre reinforced SCHPC (HFSCHPC) after heating were better than that of mono fibre reinforced SCHPC. The failure mode changed from pull-out of steel fibres at lower temperature to broken down of steel fibres at higher temperature. The use of hybrid fibre can be effective in providing the residual strength and failure pattern and in improving the toughness and fracture energy of SCHPC after high temperature.

Increasingly in a society with a high growth rate and standards of comfort, the need to minimize the currently high energy consumption by taking advantage of renewable energy sources arises. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing for an increase in the level of thermal comfort and reduction of the use of heating, ventilation and air conditioning (HVAC) equipment, using only the energy supplied by the sun. However, the incorporation of PCM in mortars modifies some of its characteristics. Therefore, the main objective of this study was the characterization of mortars doped with two different phase change materials. Specific properties of different PCM, such as particle size, shape and enthalpy were studied, as well as the properties of the fresh and hardened state of these mortars. Nine different compositions were developed which were initially doped with microcapsules of PCM A and subsequently doped with microcapsules of PCM B. It was possible to observe that the incorporation of phase change materials in mortars causes differences in properties such as compressive strength, flexural strength and shrinkage. After the study of the behaviour of these mortars with the incorporation of two different phase change materials, it was possible to select the composition with a better compromise between its aesthetic appearance, physical and mechanical characteristics.