Crushed rock seems the obvious way to make aggregate in rock abundant Scandinavia, but it was not always so. Adrian Greeman reports
It is perhaps not surprising that in Sweden the crushed rock quarry dominates aggregate production as, like most of Scandinavia, the country comprises virtually all hard rock once you pass through a relatively thin overburden. Most of these rock deposits, though not all, of it are very suitable for crushing as construction aggregates.
But while around 80% of today's aggregate production in Sweden comes from crushing, it was not always so - just 30 years ago, most production was from gravel pits and sand deposits.
The reason for this is geographic - most of the deposits were in the southern area and much of the country's nearly 9million population lives in this region with the major cities of Stockholm, Gothenberg and Malmo.
Hundreds of small gravel pits served construction in these areas and saw something of a boom period in the 1970s when a government sponsored housebuilding programme was pushed through. "There was insufficient housing in the post-war decades and we had a 'million dwellings' programme," explained Swedish Aggregate Producers Association director Björn Strokirk.
Demand
"Production reached around 130million tonnes annually to service mainly concrete production but it tailed off in the 1980s as the programme ended and there was a recession economically." Production dropped back and output levels varied between 70million tonnes to a high of 100million tonnes in the early 1990s. Another fall in figures has given way recently to a steady climb in output to over 90million tonnes in 2006, when the last official figures were published "But it has grown since then to reach 99.4million tonnes in 2007 and 101.4million tonnes in 2008," said Strokirk. He thinks that this trend will not continue in the 2009 figures which could be between 10-20% less as the impact of the economic crisis is felt.
"It is not clear how much the industry will be affected yet because there is a lag in the contracts, and many of them do not run out immediately," said Mattias Göransson, an aggregates specialist at the Swedish Geological Survey.
Leaving aside the economic downturn there has been a marked change in the industry over the decades. Two interlinked trends are noticeable - a transition to crushed rock production and the consolidation of the industry.
"Quarries tend to be bigger and require more investment both in the size of the facility and the time span, and in the equipment to run it," said Göransson.
Jan Bida who works for specialist consultant SBMI said, "There are also synergies and economy of scale effects which help." One he pointed to is the use of mobile crushing units which can be used in up to half a dozen different quarries in a year. "They build up a stockpile and then move on, leaving a loader on site to service deliveries," he said.
Nonetheless, Strokirk added that there are still a lot of smaller family gravel firms. "But the number is diminishing as the natural aggregates side goes down," he said.
The total number of quarries producing aggregates in Sweden was just over 2000 in 2008, down somewhat from 3721 licensed sites recorded decade earlier, according to figures from the Geological Survey.
The top ten producers include some very large firms such as
According to Strokirk, only the largest producers are members of the association. "There are 70 members but between them they produce about 75% of the output," he said.
Highway construction
The road administration interest is significant as it is road building demand which has largely contributed to the change from natural aggregate to crushed rock aggregates. For asphalt and sub-base the SRA insists on crushed aggregates for road construction because of the structural advantages over natural gravel aggregates.
As with much construction in Scandinavia, the rock geomorphology means that projects very often involve blasted cuttings or even tunnel and a significant proportion of aggregate comes from this activity.
Increasingly too, the waste from Sweden's substantial mining industry is being looked at as potential source material. Until recently this was unfeasible because the major extraction, such as at the famous giant underground iron ore complex at Kiruna near the Arctic Circle, is too far away.
"The rock at Kiruna is very good quality for aggregate - it is a porphyry, said Bida. But transport costs are a huge proportion of the final delivered aggregate cost and delivery is rarely beyond a 25 to 30km radius.
Until recently the railway network has not been suitable and about 99% of all aggregate goes by truck, according Göransson. But a project is being planned to build a new branch line to the main north-south rail line with a new loading depot at the Aitec open cast copper mine some 100km from Kiruna.
But complementing these factors has been a deliberate drive by Sweden's administration to cut down the use of natural aggregate. According to Bida, the prime purpose is preservation of water aquifers. "We are lucky that nearly all the water we drink here can be virtually unprocessed and there is drive to sustain that by reducing gravel pit extraction," he said.
Environment
"The move came long before Europe-wide water sustainability legislation. Already in the mid 1990s a target was set to reduce natural aggregate use to 12millon tonnes by this year and shortly afterwards a tax was introduced at an initial level of €0.3/tonne, which has since risen to €1.3/tonne." However, the drive to reduce natural aggregate has only been partially successful, according to Göransson, as 19million tonnes is still used annually. "The problem is that it is economically, and sometimes technically, impractical to always use crushed rock as it is more expensive and usually has higher transport costs," he said.
"For concrete especially there is a need for rounded sand rather than sharp edged crushed sand. Also the mica content in some rock also means it must go through additional processing to be usable." The industry would like to see the tax removed as it is believed that the road specifications have been a more significant factor in changing things. But the environmental lobby would like to see it increased. The specialist crushed rock operators, which produce some 2million tonnes of manufactured sand annually would also like to see the tax increased, arguing that it would better balance out costs. The issue may be resolved later this year after an election that could include the Green Party in a coalition government.
Meanwhile like the industry elsewhere, the producers in Sweden are beset by the NIMBY problem when applying for permission to open new quarries. Permits are usually granted after a relatively straightforward two to four year process that includes preparation of increasingly expensive environmental impact statements. These statements cannot be done without a specialist consultant and usually require a restoration plan and set aside of funds to achieve it.
But the county authorities, who are the first decision makers, have the right to declare that their area has no need of more production. The industry disagrees with this right as it is thought that if a producer has decided to make a big investment, it is only because there is a market need. "We are not producing this to use it ourselves," said NCC's Sven Wallman.
There is provision to contest a county decision in one of five regional Environmental Courts which were created in the late 1990s as part of a radical restructuring of the law in this area. And if that fails it might be possible to appeal the national Upper Environmental Court.
But this is expensive and the
A final issue he thinks is important currently is the improvement in health and safety measures and general working conditions in the industry. "An older workforce is coming up to retirement and it is crucial to attract in a more choosy younger generation," said Strokirk.
FACT FILE: SCANDINAVIA
No. of operators 150
No. of quarries 1840
No. of employees:3500
Total production: 80 million tonnes
Sand and gravel: 23 million tonnes
Crushed rock: 49 million tones
Recycled aggregates: 8 million tonnes
Source: UEPG 2006
