不同粒石堆疊多孔表層蒸發孔隙性之實驗研究

An Experimental Study on Evaporosity of Different Packing Granular Stone Porous Surface Layers

善用蒸發降水循環平衡來修復氣候是水的新範式，加強蒸發冷卻調濕熱以緩和都市熱島效應是有效的環境對策。環境中，太陽輻射能的可獲性、空氣溼度梯度、風速大小和供持水的充足度等是水蒸發的關鍵條件，而建築表層中各種尺度的多孔隙性堆疊構築區塊，其持水多孔表層正可構成水分子相變汽化的通道平台，形成蒸發面，藉前述迎陽、乘風、透氣和曝濕等蒸發條件，提高蒸發水勢能，讓水分子持續向上運動，促進蒸發及冷卻。蒸發面表層可由具特定質地、形狀、尺寸與表面的構材顆粒堆叠成特定的形態與空間結構，顯現其孔隙特性，本研究即旨在探討此具蒸發條件能力的孔隙特性—合稱蒸發孔隙性，並先以不同粒石堆疊多孔表層為基本構築區塊，進行研究。本研究發展了一個可供參照的水蒸發率量測方法，以歷經68天的六輪實驗，量測分析23樣不同粒石堆疊多孔表層試材及水隨天氣與時間變化的蒸發率，取得60組數據資料，並以理論模型模擬及儀器分析去印證實驗結果。研究發現，孔隙孔徑與連通性、鋪層表面積、橫截面間隙比例、通氣孔隙率、容積密度、有效蒸發表層厚度與粒徑及堆疊孔隙構成等，是多孔表層顯現蒸發孔隙性的七個重要因素，而在各試材中，內含連通孔的廢棄混凝土呈現了較大蒸發率與較佳的蒸發孔隙性，有再利用意義，最值得後續研究。

A new water paradigm is that water cycling could be solution for the recovery of climate. Enhancing evaporation rates to produce evaporative cooling effect is an efficient environmental strategy to help mitigating urban heat island effect. This study, combined evaporation and porosity as evaporosity, is aim to find the tectonics of evaporosity in basic building blocks for enhancing evaporation rate. A simple experiment method was used to explore the evaporation rates of 23 different packing granular stone porous surface layers plus bare water. 60 experimental results of evaporation rates were obtained during 68 days. The finding implied that there were 7 main factors of the tectonics of evaporosity and the recycled concrete granule, having better evaporation rate and evaporosity, was highly recommended for further studies.