Microstructural study of Styrene Polyacrylic (SPA) latex modified mortars

In this paper, the influence of the styrene polyacrylic (SPA) latex polymer on the microstructural properties of limestone mortars has been studied. For this purpose, five mortars were developed with different dosages of the SPA latex (0%, 2.5%, 5%, 7.5% and 10%) by weight of cement. This research was carried out using XRD, FTIR, and SEM analyses. The results of XRD and FTIR studies showed that the addition of SPA latex can increase the portlandite content of polymer-modified mortars (PMMs), compared to the control mortar. In addition, the moist environment promotes the Ca(OH)2 consumption in PMMs at early age and accelerates the hydration. Moreover, the SEM analysis revealed that the cement hydrate structure of the reference mortar is loose. In contrast, the hydrates of the PMMs were covered by a polymer film or membrane, and the pore structure is significantly affected by the filling effect the micropores by the latex particles

Microstructural study of Styrene Polyacrylic (SPA) latex modified mortars

In this paper, the influence of the styrene polyacrylic (SPA) latex polymer on the microstructural properties of limestone mortars has been studied. For this purpose, five mortars were developed with different dosages of the SPA latex (0%, 2.5%, 5%, 7.5% and 10%) by weight of cement. This research was carried out using XRD, FTIR, and SEM analyses. The results of XRD and FTIR studies showed that the addition of SPA latex can increase the portlandite content of polymer-modified mortars (PMMs), compared to the control mortar. In addition, the moist environment promotes the Ca(OH)2 consumption in PMMs at early age and accelerates the hydration. Moreover, the SEM analysis revealed that the cement hydrate structure of the reference mortar is loose. In contrast, the hydrates of the PMMs were covered by a polymer film or membrane, and the pore structure is significantly affected by the filling effect the micropores by the latex particles

Mix proportioning and performance of a crushed limestone sand-concrete

Satisfying the ever-growing demand of concrete aggregates poses a problem in many parts of the world due to shortage of natural sand. Moreover, to conserve natural resources and protect civil engineering infrastructures, there is a need to find alternative materials. Crushed stone sand has been identified as a potential substitute material for natural sand in making good quality concrete. The main objective of the present investigation is to determine an adequate mix design method and evaluate engineering properties of crushed limestone sand concrete mixtures in both the fresh and hardened sates. More than thirty concrete mixtures were examined. The results indicate that water demand and cement paste content in crushed sand concrete are generally higher than that used in similar conventional concrete. Good mechanical properties were obtained for concrete using crushed limestone sand as fine aggregates with a superplasticizer. However, a higher than normally used dosage of superplasticizer is required in these concrete mixtures and the optimum dosage of the superplasticizer needs to be determined for each cement and sand content

The Rehabilitation effects on the thermal behaviour of Algerian earthen built heritage.

The earthen built heritage presents today a state of deterioration due to the climate changes that put it seriously at risk, through the degradation of its envelope building materials. These degradations lead its occupants to rehabilitate it by using modern building materials. This paper focuses on the rehabilitation of vernacular earthen architecture and its influence on the thermal behaviour of ksourian houses in sub-arid zones. It is based on a comparative study that combines the site measurements and the numerical simulation by Energyplus. Two courtyard houses, constructed of an adobe brick, were evaluated, one in its initial shape and the other rehabilitated. The results shows that the rehabilitation of the envelope made on this house did not influence its thermal qualities significantly; a very small difference justified on its internal thermal behaviour was recorded in cold period and almost minor during summer

The Rehabilitation effects on the thermal behaviour of Algerian earthen built heritage.

The earthen built heritage presents today a state of deterioration due to the climate changes that put it seriously at risk, through the degradation of its envelope building materials. These degradations lead its occupants to rehabilitate it by using modern building materials. This paper focuses on the rehabilitation of vernacular earthen architecture and its influence on the thermal behaviour of ksourian houses in sub-arid zones. It is based on a comparative study that combines the site measurements and the numerical simulation by Energyplus. Two courtyard houses, constructed of an adobe brick, were evaluated, one in its initial shape and the other rehabilitated. The results shows that the rehabilitation of the envelope made on this house did not influence its thermal qualities significantly; a very small difference justified on its internal thermal behaviour was recorded in cold period and almost minor during summer