With constraints on both traditional inland sources and regional trade, China will seek potential substitutes for fine concrete aggregate. Both natural and artificial alternatives to river and lake sand are available, but many of these are not sufficient in structural applications (see Appendix A). For example, dune sand taken from desert sources does not bind well in concrete mix and may only compose a small percentage of aggregate. Similarly, recycled sand may only be used at a ratio of 20 to 30 percent. Dredging sand from beaches is problematic due to coastal erosion and is an illegal practice in China. Crushed stone and offshore marine sand deposits present the most viable substitutes for fine aggregate, although each of these are not without limitations

Fine concrete aggregate may be produced artificially by crushing stone to a standard size. Manmade sand is expected to gain market share as the country’s inland rivers and lakes are further depleted, although natural sand remains the most highly consumed construction aggregate in China. Manufactured sand is a promising substitute for fine concrete aggregate, but has not yet gained a strong foothold in Asia. Specifically, the use of crushed stone in concrete mix is not commonly accepted in China’s construction industry for the following reason

• Inconsistent quality across localities. While rock quarries are relatively abundant, unfavorable geographic distribution may limit the availability of quality material near the site of construction. Often, crushed stone must be blended with natural sand to achieve appropriate grading and workability. Moreover, urban encroachment and land-use conflicts result in local shortages, raising prices for crushed stone suitable for concrete production. Concrete made with crushed stone is also costly because it requires more cement to account for its poor shape.

• High cost of production and transport. Although access to Chinese data is limited, U.S. prices for concrete aggregate are available. In the United States, crushed stone currently sells for 10.46 USD per metric ton, whereas natural sand sells for only 7.72 USD. Crushing, screening, and washing quarried rock is an added expense that is reflected in the relatively high price of manufactured sand. Transportation costs are also significant. Proximity to local markets is key, and most aggregates are not shipped further than 35 to 50 miles from where they are excavated.37 Otherwise, the cost of transport may exceed that of the material itself. Especially with increased migration to urban centers in China, quarries near the site of construction undergo more rapid rates of depletion.

• Insufficient supply to meet market demand. Manufactured sand that is produced from quality material and processed appropriately may act as a perfect substitute for natural sand in concrete. However, if crushed stone is indeed used as a total replacement for fine aggregate, most rock quarries would only be capable of meeting 30 to 50 percent of market demand. Switching costs also provide a barrier to adaptation. The construction industry is relatively conservative and risk-adverse, and as such, is reluctant to change well-known practices to accommodate new materials in concrete production

Japan is the only country in Asia that has managed a successful transition to manufactured sand. In 1990, Tokyo banned all dredging activities to preserve the country’s extremely limited natural resources.

Marine sand contains chlorides, which cause corrosion in steel. Over a period of 25 to 30 years, structural damage may render buildings at risk of collapse. If washed to remove chloride, marine sand that meets standard size may reliably contribute up to 100 percent of fine concrete aggregate—although this is an expensive process because of the amount of water required.

Despite the hazards of using raw marine sources for fine aggregate, Chinese builders have demonstrated a willingness to sacrifice quality—risking long-term structural integrity—to reduce short-term costs

China has already developed the capacity for large-scale dredging in the SCS and may redirect its island-building efforts to benefit the country’s construction industry. Over the past 15 years, Beijing’s dredging operations have drastically outpaced those of other states in the region. China has assembled a large fleet of sea-going vessels that can pump material directly from the ocean floor. For example, the specialized dredger Tianjing is Asia’s largest and can move over 100,000 cubic meters of sand every day. The country’s annual dredging volume more than tripled over an over an eight-year period from 300 million cubic meters in 2001 to one billion cubic meters in 2009

Up to 90% of natural sand beaches could be taken

Due to natural erosion stemming from storms, tides, tornados, tsunamis, and rising sea levels, beaches are subject to constant attack. Because of these natural phenomena, large beach lines have been refurbished for decades in countries ranging from the USA to Indonesia in order to keep their pristine tourist destinations alive.

Despite this effort, an estimated 75 to 90 percent of the world’s natural sand beaches are about to vanish.

Illegal sand mining, defined as the stealing of sand or simply beach theft, has wreaked havoc in many parts of the world. Since the mid 2000s, illegal mining has caused severe local supply shortages and the destruction of multiple beach areas and coast lines across the globe.

200 tons of sand in an average single family house

Sand is one key component to mix concrete. However, desert sand, which seems to stretch across the globe forever, does not serve this purpose due to its consistency and chemical properties. This is mainly due to its lack of silicon dioxide compounds, and the fact that desert sand is too fine and smooth, containing too much clay, iron oxides and lime.

By contrast, sand that is extracted from the bottom of oceans, beaches, rivers and gravel beds consists of minerals and metals such as titanium, thorium, silicon and uranium, which play a more crucial role in our daily life than most of us can imagine.

These mineral and metal components are used to manufacture microchips, silicon chips and solar panels, build houses or aircrafts, and to produce cosmetics, abrasives, glass, plastics, and toothpaste. On average, one single-family house builds in about 200 tons of sand.

A cornerstone of China’s domestic infrastructure policy is to accelerate urbanization, connecting its remote areas with highly developed cities in the Southeast, along the coastline, and around the Yangtze River. China is also building up five clusters of mega cities, which will provide living and working space for more than 500 million people.

According to Global Construction 2025, emerging construction markets will see growth of 3 to 6% per year. In total, construction in 2025 is expected to exceed the value of $15 trillion. Sub-Saharan Africa is predicted to be the second-highest growth region, and China alone will account for 25% of global construction activity.