Methods of producing construction elements, construction elements produced thereby, and structures produced therefrom
Processes for incorporating phase change materials (PCM) into porous construction elements, composite construction elements produced thereby, and structures constructed therefrom. Such a process includes heating a PCM to a temperature at or above a melting temperature thereof to liquify the PCM and yield a liquid PCM, fully immersing a porous construction element in the liquid PCM, and infiltrating the liquid PCM into porosity of the construction element while the construction element and liquid PCM are at a subatmospheric pressure level and at a temperature sufficient to maintain the PCM in a liquid state to yield a composite construction element in which the porosity of the construction element has been at least partially filled with the PCM. Such a composite construction element is preferably capable of increasing the thermal inertia of a building envelope constructed therefrom with little or no detrimental effects on properties of the construction elements.
1 . A process of producing a construction element, the process comprising:
providing a pre-existing construction element that contains porosity;
heating a PCM to a temperature at or above a melting temperature thereof to liquify the PCM and yield a liquid PCM;
fully immersing the pre-existing construction element in the liquid PCM; and
infiltrating the liquid PCM into the porosity of the pre-existing construction element while the pre-existing construction element and the liquid PCM are at a subatmospheric pressure level and at a temperature sufficient to maintain the PCM in a liquid state to yield a composite construction element in which the porosity of the pre-existing construction element is at least partially filled with the PCM, wherein the infiltration of the liquid PCM into the porosity of the pre-existing construction element is limited to surface regions of the pre-existing construction element exposed to the liquid PCM such that the PCM is concentrated in the surface regions and is not uniformly distributed within an interior of the composite construction element.
2 . The process of claim 1 , wherein the PCM is an organic hydrocarbon.
3 . The process of claim 1 , wherein the pre-existing construction element is chosen from the group consisting of bricks, panels, blocks, preformed walls, drywall, pavers, and roof shingles.
4 . The process of claim 1 , further comprising preheating the pre-existing construction element before the immersing step.
5 . The process of claim 1 , wherein the thermal inertia of the composite construction element is greater than the thermal inertia of the pre-existing construction element prior to the immersing step.
6 . The process of claim 1 , wherein the composite construction element exhibits lower porosity, lower permeability, higher durability, and equal or higher strength than the pre-existing construction element.
7 . The process of claim 1 , further comprising using a plurality of the composite construction elements as pavers to construct a walkway.
8 . The process of claim 7 , wherein the pavers reduce ice formation and improve durability and performance of the walkway.
9 . The process of claim 1 , further comprising using a plurality of the composite construction element to construct a building.
10 . The process of claim 9 , wherein the plurality of the composite construction element reduces heating and cooling energy usage of the building.
11 . The process of claim 9 , wherein the pre-existing construction element is formed of a recycled aggregate and the plurality of the composite construction element reduces an environmental footprint of the building.
12 . The process of claim 1 , wherein the pre-existing construction element is composed at least partially of Portland cement.
13 . The process of claim 12 , wherein the pre-existing construction element has a water-to-cement ratio between 0.45 and 0.65.
14 . The process of claim 13 , wherein the pre-existing construction element is immersed for about 15 minutes to 4 hours.
15 . The process of claim 1 , wherein the pre-existing construction element is at least partially of quarzitic natural fine aggregate.
16 . The process of claim 1 , wherein the pre-existing construction element is heated to the same temperature as the PCM before being immersed in it.